INTEGR1C

index · ← DILWORTH · INTERVA1 →
:: Complex Integral
::  by Masahiko Yamazaki , Hiroshi Yamazaki , Katsumi Wasaki and Yasunari Shidama
::
:: Received October 10, 2009
:: Copyright (c) 2009-2026 Association of Mizar Users
::           (Stowarzyszenie Uzytkownikow Mizara, Bialystok, Poland).
:: This code can be distributed under the GNU General Public Licence
:: version 3.0 or later, or the Creative Commons Attribution-ShareAlike
:: License version 3.0 or later, subject to the binding interpretation
:: detailed in file COPYING.interpretation.
:: See COPYING.GPL and COPYING.CC-BY-SA for the full text of these
:: licenses, or see http://www.gnu.org/licenses/gpl.html and
:: http://creativecommons.org/licenses/by-sa/3.0/.

environ

 vocabularies NUMBERS, SUBSET_1, FDIFF_1, SEQ_1, FUNCT_1, ZFMISC_1, MCART_1,
      ARYTM_3, RELAT_1, XCMPLX_0, REAL_1, PARTFUN1, INTEGRA1, COMPLEX1,
      VALUED_1, ARYTM_1, XBOOLE_0, TARSKI, XXREAL_0, XXREAL_1, RCOMP_1,
      ORDINAL2, SIN_COS, CARD_1, FDIFF_3, FUNCT_2, SEQ_2, TOPMETR, INTEGRA5,
      VFUNCT_1, XXREAL_2, INTEGR1C, MEASURE5, VALUED_0, NAT_1;
 notations TARSKI, XBOOLE_0, ZFMISC_1, XTUPLE_0, SUBSET_1, RELAT_1, FUNCT_1,
      RELSET_1, VALUED_0, FUNCT_3, PARTFUN1, FUNCT_2, ORDINAL1, NUMBERS,
      XCMPLX_0, XREAL_0, XXREAL_0, COMPLEX1, REAL_1, BINOP_1, RCOMP_1, SEQ_1,
      SEQ_2, FCONT_1, FDIFF_1, COMSEQ_3, TOPMETR, MCART_1, MEASURE5, INTEGRA5,
      SIN_COS, VALUED_1, PRE_TOPC, FDIFF_3, STRUCT_0, XXREAL_2;
 constructors REAL_1, FDIFF_1, RFUNCT_3, FCONT_1, INTEGRA5, SIN_COS, TOPMETR,
      FDIFF_3, MESFUN6C, SEQ_2, RVSUM_1, COMSEQ_3, INTEGRA1, COMSEQ_2,
      XTUPLE_0, BINOP_2, BINOP_1;
 registrations XREAL_0, FUNCT_2, NUMBERS, ORDINAL1, MEMBERED, SIN_COS, FDIFF_1,
      SUBSET_1, XCMPLX_0, RELAT_1, XXREAL_0, XBOOLE_0, VALUED_0, VALUED_1,
      RELSET_1, MEASURE5, XTUPLE_0;
 requirements NUMERALS, BOOLE, SUBSET, REAL, ARITHM;
 definitions TARSKI;
 equalities INTEGRA5, VALUED_1;
 expansions TARSKI;
 theorems ZFMISC_1, XCMPLX_0, TOPMETR, SEQ_4, INTEGRA1, RFUNCT_1, FUNCT_1,
      SEQ_1, SEQ_2, FDIFF_1, ABSVALUE, COMPLEX1, FUNCT_3, TARSKI, RCOMP_1,
      FCONT_1, RFUNCT_2, FDIFF_2, RELAT_1, XXREAL_1, FUNCT_2, NUMBERS,
      XBOOLE_0, XBOOLE_1, XREAL_1, INTEGRA5, SIN_COS, INTEGRA6, CFUNCT_1,
      VALUED_1, MESFUN6C, TOPS_1, FDIFF_3, RELSET_1, XXREAL_2, MCART_1,
      BORSUK_5, COMSEQ_3, MEASURE5, XREAL_0, ORDINAL1;
 schemes FUNCT_2, FUNCT_7;

begin :: The Definition of Complex Curve and Complex Integral

reserve n,n1,m for Element of NAT;
reserve r,t,x1 for Real;
reserve h for 0-convergent non-zero Real_Sequence;
reserve c1 for constant Real_Sequence;
reserve p1 for Real;

definition
  func R2-to-C -> Function of [:REAL,REAL:],COMPLEX means :Def1:
  for p be Element of [:REAL,REAL:], a,b be Element of REAL st
  a = p`1 & b = p`2 holds
  it.([a,b]) = a+b*<i>;
  existence
    proof
      deffunc F(Real,Real)
      = $1+$2*<i>;
A1: for x being Element of REAL, y being Element of REAL holds
    F(x,y) in COMPLEX by XCMPLX_0:def 2;
    consider
    f being Function of [:REAL,REAL:],COMPLEX such that
A2: for x,y being Element of REAL
    holds f.(x,y) = F(x,y) from FUNCT_7:sch 1(A1);
    deffunc G(Element of [:REAL,REAL:]) = f.($1`1,$1`2);
A3: now let p being Element of [:REAL,REAL:];
      p`1 is Element of REAL & p`2 is Element of REAL by MCART_1:10;then
      consider a,b be Element of REAL such that
A4:   a = p`1 & b = p`2;
      G(p) = a + b*<i> by A2,A4;
      hence G(p) in COMPLEX by XCMPLX_0:def 2;
    end;
    consider g being Function of [:REAL,REAL:], COMPLEX such that
A5: for p being Element of [:REAL,REAL:]
    holds g.p = G(p) from FUNCT_2:sch 8(A3);
    take g;
    for p be Element of [:REAL,REAL:], a,b be Element of REAL st
    a = p`1 & b = p`2 holds
    g.([a,b]) =a+b*<i>
      proof
        let p be Element of [:REAL,REAL:],
        a,b be Element of REAL such that
A6:     a = p`1 & b = p`2;
A8:     [a,b] is Element of [:REAL,REAL:] by ZFMISC_1:def 2;
A9:     [a,b]`1 = p`1 by A6;
        [a,b]`2 = p`2 by A6;then
        g.([a,b]) = f.(a,b) by A5,A8,A9
        .= a+b*<i> by A2;
        hence thesis;
      end;
    hence thesis;
  end;
  uniqueness
  proof
    let f,g be Function of [:REAL,REAL:],COMPLEX;
    assume
A10: for p be Element of [:REAL,REAL:],
    a,b be Element of REAL st a = p`1 & b = p`2
    holds f.([a,b]) = a+b*<i>;
    assume
A11: for p be Element of [:REAL,REAL:],
    a,b be Element of REAL st a = p`1 & b = p`2
    holds g.([a,b]) = a+b*<i>;
    for p0 be object st p0 in [:REAL,REAL:] holds f.p0 = g.p0
      proof
        let p0 be object;
        assume
A12:    p0 in [:REAL,REAL:];then
        consider x0,y0 be object such that
A13:    x0 in REAL & y0 in REAL & p0 = [x0,y0] by ZFMISC_1:def 2;
        reconsider a = x0,b = y0 as Element of REAL by A13;
A14:    p0`1 = a by A13;
A15:    p0`2 = b by A13;
        then f.p0 = a+b*<i> by A12,A10,A14,A13
        .= g.p0 by A13,A12,A11,A14,A15;
        hence thesis;
      end;
    hence f = g by FUNCT_2:12;
  end;
end;

definition
  let a,b be Real;
  let x,y be PartFunc of REAL,REAL, Z be Subset of REAL;
  let f be PartFunc of COMPLEX, COMPLEX;
  func integral(f,x,y,a,b,Z) -> Complex means :Def2:
  ex u0, v0 be PartFunc of REAL,REAL st
  u0 = (Re f)* (R2-to-C) *<:x,y:> & v0 = (Im f)* (R2-to-C) *<:x,y:> &
  it = integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i>;
  existence
    proof
A1:   dom <:x,y:> = dom x /\ dom y by FUNCT_3:def 7;
      rng <:x,y:> c= [:rng x,rng y:] by FUNCT_3:51;then
      rng <:x,y:> c= [:REAL,REAL:] by XBOOLE_1:1;then
      reconsider xy=<:x,y:> as PartFunc of REAL,[:REAL,REAL:]
      by A1,RELSET_1:4;
      (Re f)* (R2-to-C) *xy is PartFunc of REAL,REAL;then
      reconsider u0=(Re f)* (R2-to-C) *<:x,y:> as PartFunc of REAL,REAL;
      (Im f)* (R2-to-C) *xy is PartFunc of REAL,REAL;
      then
      reconsider v0=(Im f)* (R2-to-C) *<:x,y:> as PartFunc of REAL,REAL;
      integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
      + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i>
      is Complex;
      hence thesis;
    end;
  uniqueness;
end;

definition
  let C be PartFunc of REAL,COMPLEX;
  attr C is C1-curve-like means :Def3:
  ex a,b be Real,
   x,y be PartFunc of REAL,REAL, Z be Subset of REAL st
  a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous & y`|Z is continuous &
  C = (x+<i>(#)y) | [.a,b.];
end;

registration
  cluster C1-curve-like for PartFunc of REAL,COMPLEX;
  existence
    proof
      set a = 1, b = 2;
      set x = cos, y = sin;
      set Z = ].-5,5.[; ::!!!!
      consider C be PartFunc of REAL,COMPLEX such that
A1:   C = (x+<i>(#)y) | [.a,b.];
      take C;
A2:   dom (x+<i>(#)y) = REAL by FUNCT_2:def 1;
      dom C = dom (x+<i>(#)y) /\ [.a,b.] by A1,RELAT_1:61;then
A3:   [.a,b.] = dom C by A2,XBOOLE_1:28;
A4:   Z is open by RCOMP_1:7;
A5:   [.a,b.] c= Z by XXREAL_1:47;
A6:   x is_differentiable_on Z by A4,FDIFF_1:26,SIN_COS:67;
A7:  y is_differentiable_on Z by A4,FDIFF_1:26,SIN_COS:68;
  sin = sin|(REAL);
      then sin|Z is continuous by FCONT_1:16;then
      (-sin)|Z is continuous by FCONT_1:21,SIN_COS:24;then
A8:  -sin|Z is continuous by RFUNCT_1:46;
A9:  dom(-sin|Z) = dom((-sin)|Z) by RFUNCT_1:46
      .= dom(-sin) /\ Z by RELAT_1:61
      .= REAL /\ Z by SIN_COS:24,VALUED_1:8
      .= Z by XBOOLE_1:28;
      for x1 st x1 in Z holds (-sin|Z).x1 = diff(x,x1)
        proof
          let x1 such that
A10:      x1 in Z;
       reconsider x1 as Element of REAL by XREAL_0:def 1;
A11:      (-sin|Z).x1 = ((-sin)|Z).x1 by RFUNCT_1:46
          .= (-sin).x1 by A10,FUNCT_1:49
          .= -(sin.x1) by RFUNCT_1:58
          .= -sin|Z.x1 by A10,FUNCT_1:49;
          diff(x,x1) = -sin.x1 by SIN_COS:67
          .= (-sin|Z).x1 by A11,A10,FUNCT_1:49;
          hence thesis;
        end; then
A12:  x`|Z is continuous by A6,A8,A9,FDIFF_1:def 7;
  cos = cos|(REAL);
then A13:  cos|Z is continuous by FCONT_1:16;
A14:  dom(cos|Z) = dom(cos) /\ Z by RELAT_1:61
      .= Z by SIN_COS:24,XBOOLE_1:28;
      for x1 st x1 in Z holds (cos|Z).x1 = diff(y,x1)
      proof
        let x1 such that
A15:    x1 in Z;
        diff(y,x1) = cos.x1 by SIN_COS:68
          .= (cos|Z).x1 by A15,FUNCT_1:49;
        hence thesis;
      end;
    then y`|Z is continuous by A7,A13,A14,FDIFF_1:def 7;
    hence thesis by A1,A3,A4,A5,A6,A7,A12,SIN_COS:24;
  end;
end;

definition
  mode C1-curve is C1-curve-like PartFunc of REAL,COMPLEX;
end;

Lm1: for a,b be Real, x,y be PartFunc of REAL,REAL, Z1,Z2 be Subset of REAL,
f be PartFunc of COMPLEX, COMPLEX st
a <= b & [.a,b.] c= dom x & [.a,b.] c= dom y &
Z1 is open & Z2 is open & [.a,b.] c= Z1 & Z1 c= Z2 &
x is_differentiable_on Z2 & y is_differentiable_on Z2 &
rng ( (x + <i>(#)y) | [.a,b.] ) c= dom f
holds
integral(f,x,y,a,b,Z1) = integral(f,x,y,a,b,Z2)
proof
  let a,b be Real,
  x,y be PartFunc of REAL,REAL,
  Z1,Z2 be Subset of REAL,
  f be PartFunc of COMPLEX, COMPLEX;
  assume
A1: a <= b & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z1 is open & Z2 is open & [.a,b.] c= Z1 & Z1 c= Z2 &
  x is_differentiable_on Z2 & y is_differentiable_on Z2 &
  rng ( (x + <i>(#)y) | [.a,b.] ) c=dom f;
then
A2: x is_differentiable_on Z1 & y is_differentiable_on Z1 by FDIFF_1:26;
  consider u01,v01 be PartFunc of REAL,REAL such that
A3: u01=(Re f)* (R2-to-C) *<:x,y:> & v01=(Im f)* (R2-to-C) *<:x,y:> &
  integral(f,x,y,a,b,Z1)= integral( u01(#)(x`|Z1) - v01(#)(y`|Z1) ,a,b )
  + integral( v01(#)(x`|Z1) + u01(#)(y`|Z1),a,b )*<i> by Def2;
  consider u02,v02 be PartFunc of REAL,REAL such that
A4: u02=(Re f)* (R2-to-C) *<:x,y:> & v02=(Im f)* (R2-to-C) *<:x,y:> &
  integral(f,x,y,a,b,Z2)= integral( u02(#)(x`|Z2) - v02(#)(y`|Z2) ,a,b )
  + integral( v02(#)(x`|Z2) + u02(#)(y`|Z2) ,a,b )*<i> by Def2;
  reconsider AB=[.a,b.] as non empty closed_interval Subset of REAL
  by A1,MEASURE5:14;
A5: (u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB = (u02(#)(x`|Z2) - v02(#)(y`|Z2)) | AB
    proof
      dom(u01(#)(x`|Z1) - v01(#)(y`|Z1))
      = dom(u01(#)(x`|Z1)) /\ dom(v01(#)(y`|Z1)) by VALUED_1:12
      .= (dom u01 /\ dom(x`|Z1)) /\ dom(v01(#)(y`|Z1)) by VALUED_1:def 4
      .= (dom u01 /\ dom(x`|Z1)) /\ (dom v01 /\ dom (y`|Z1))
      by VALUED_1:def 4;then
A6:   dom(u01(#)(x`|Z1) - v01(#)(y`|Z1))
      = (dom u01 /\ Z1) /\ ( dom v01 /\ dom(y`|Z1)) by A2,FDIFF_1:def 7
      .= (dom u01 /\ Z1) /\ ( dom v01 /\ Z1) by A2,FDIFF_1:def 7
      .= dom u01 /\ (Z1 /\ ( dom v01 /\ Z1)) by XBOOLE_1:16
      .= dom u01 /\ ((Z1 /\ Z1 ) /\ dom v01) by XBOOLE_1:16
      .= (dom u01 /\ dom v01) /\ Z1 by XBOOLE_1:16;
      dom(u02(#)(x`|Z2) - v02(#)(y`|Z2))
      = dom(u02(#)(x`|Z2)) /\ dom(v02(#)(y`|Z2)) by VALUED_1:12
      .= (dom u02 /\ dom(x`|Z2)) /\ dom(v02(#)(y`|Z2)) by VALUED_1:def 4
      .= (dom u02 /\ dom(x`|Z2)) /\ (dom v02 /\ dom (y`|Z2))
      by VALUED_1:def 4;then
A7:   dom(u02(#)(x`|Z2) - v02(#)(y`|Z2))
      = (dom u02 /\ Z2) /\ ( dom v02 /\ dom(y`|Z2)) by A1,FDIFF_1:def 7
      .= (dom u02 /\ Z2) /\ ( dom v02 /\ Z2) by A1,FDIFF_1:def 7
      .= dom u02 /\ (Z2 /\ ( dom v02 /\ Z2)) by XBOOLE_1:16
      .= dom u02 /\ ((Z2 /\ Z2 ) /\ dom v02) by XBOOLE_1:16
      .= (dom u01 /\ dom v01) /\ Z2 by A3,A4,XBOOLE_1:16;
A8:   dom((u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB)
       = dom (u01(#)(x`|Z1) - v01(#)(y`|Z1)) /\ AB by RELAT_1:61
      .= (dom u01 /\ dom v01) /\ (Z1 /\ AB) by A6,XBOOLE_1:16
      .= (dom u01 /\ dom v01) /\ AB by A1,XBOOLE_1:28;
A9:   dom((u02(#)(x`|Z2) - v02(#)(y`|Z2)) | AB)
      = dom (u02(#)(x`|Z2) - v02(#)(y`|Z2)) /\ AB by RELAT_1:61
      .= (dom u01 /\ dom v01) /\ (Z2 /\ AB) by A7,XBOOLE_1:16
      .= (dom u01 /\ dom v01) /\ AB by A1,XBOOLE_1:1,28;
      for x0 being object st x0 in dom((u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB )
      holds
      ((u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB).x0
      = ((u02(#)(x`|Z2) - v02(#)(y`|Z2)) | AB ).x0
        proof
          let x0 being object such that
A10:      x0 in dom((u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB );
          x0 in dom(u01(#)(x`|Z1) - v01(#)(y`|Z1)) /\ AB by A10,RELAT_1:61;
          then
A11:      x0 in dom(u01(#)(x`|Z1) - v01(#)(y`|Z1)) by XBOOLE_0:def 4;
          then
          x0 in dom(u01(#)(x`|Z1)) /\ dom(v01(#)(y`|Z1)) by VALUED_1:12;
          then
A12:      x0 in dom(u01(#)(x`|Z1)) & x0 in dom(v01(#)(y`|Z1))
          by XBOOLE_0:def 4;then
          x0 in dom u01 /\ dom(x`|Z1) & x0 in dom v01 /\ dom(y`|Z1)
          by VALUED_1:def 4; then
          x0 in dom u01 & x0 in dom(x`|Z1)
          & x0 in dom v01 & x0 in dom(y`|Z1) by XBOOLE_0:def 4; then
A13:      x0 in Z1 by A2,FDIFF_1:def 7;
          reconsider x0 as Real by A11;
A14:      ((u01(#)(x`|Z1) - v01(#)(y`|Z1)) | AB).x0
          = (u01(#)(x`|Z1) - v01(#)(y`|Z1)).x0 by A10,FUNCT_1:47
          .= (u01(#)(x`|Z1)).x0 - (v01(#)(y`|Z1)).x0 by A11,VALUED_1:13
          .= u01.x0*(x`|Z1).x0 - (v01(#)(y`|Z1)).x0 by A12,VALUED_1:def 4
          .= u01.x0*(x`|Z1).x0 - v01.x0*(y`|Z1).x0 by A12,VALUED_1:def 4
          .= u01.x0*diff(x,x0) - v01.x0*(y`|Z1).x0 by A2,A13,FDIFF_1:def 7;
          x0 in dom(u02(#)(x`|Z2) - v02(#)(y`|Z2)) /\ AB
          by A8,A9,A10,RELAT_1:61;
          then
A15:      x0 in dom(u02(#)(x`|Z2) - v02(#)(y`|Z2)) by XBOOLE_0:def 4;
          then
          x0 in dom(u02(#)(x`|Z2)) /\ dom(v02(#)(y`|Z2)) by VALUED_1:12;
          then
A16:      x0 in dom(u02(#)(x`|Z2)) & x0 in dom(v02(#)(y`|Z2))
          by XBOOLE_0:def 4;then
          x0 in dom u02 /\ dom(x`|Z2) & x0 in dom v02 /\ dom(y`|Z2)
          by VALUED_1:def 4;then
          x0 in dom u02 & x0 in dom(x`|Z2)
          & x0 in dom v02 & x0 in dom(y`|Z2) by XBOOLE_0:def 4;then
A17:      x0 in Z2 by A1,FDIFF_1:def 7;
          ((u02(#)(x`|Z2) - v02(#)(y`|Z2)) | AB ).x0
          = (u02(#)(x`|Z2) - v02(#)(y`|Z2)).x0 by A8,A9,A10,FUNCT_1:47
          .= (u02(#)(x`|Z2)).x0 - (v02(#)(y`|Z2)).x0 by A15,VALUED_1:13
          .= u02.x0*(x`|Z2).x0 - (v02(#)(y`|Z2)).x0 by A16,VALUED_1:def 4
          .= u02.x0*(x`|Z2).x0 - v02.x0*(y`|Z2).x0 by A16,VALUED_1:def 4
          .= u02.x0*diff(x,x0) - v02.x0*(y`|Z2).x0
          by A1,A17,FDIFF_1:def 7; then
          ((u02(#)(x`|Z2) - v02(#)(y`|Z2)) | AB).x0
          = u01.x0*diff(x,x0) - v01.x0*diff(y,x0)
          by A1,A3,A4,A17,FDIFF_1:def 7;
          hence thesis by A2,A13,A14,FDIFF_1:def 7;
        end;
      hence thesis by A8,A9,FUNCT_1:def 11;
    end;
A18: integral( u01(#)(x`|Z1) - v01(#)(y`|Z1) ,a,b )
   = integral( (u01(#)(x`|Z1) - v01(#)(y`|Z1)), AB ) by INTEGRA5:19
  .= integral( u02(#)(x`|Z2) - v02(#)(y`|Z2) ,AB) by A5
  .= integral( u02(#)(x`|Z2) - v02(#)(y`|Z2) ,a,b ) by INTEGRA5:19;
A19: (v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB
  = (v02(#)(x`|Z2) + u02(#)(y`|Z2)) | AB
    proof
      dom(v01(#)(x`|Z1) + u01(#)(y`|Z1))
      = dom(v01(#)(x`|Z1)) /\ dom(u01(#)(y`|Z1)) by VALUED_1:def 1
      .= (dom v01 /\ dom(x`|Z1)) /\ dom(u01(#)(y`|Z1)) by VALUED_1:def 4
      .= (dom v01 /\ dom(x`|Z1)) /\ (dom u01 /\ dom (y`|Z1))
      by VALUED_1:def 4;then
A20:  dom(v01(#)(x`|Z1) + u01(#)(y`|Z1))
      = (dom v01 /\ Z1) /\ ( dom u01 /\ dom(y`|Z1)) by A2,FDIFF_1:def 7
      .= (dom v01 /\ Z1) /\ ( dom u01 /\ Z1) by A2,FDIFF_1:def 7
      .= dom v01 /\ (Z1 /\ ( dom u01 /\ Z1)) by XBOOLE_1:16
      .= dom v01 /\ ((Z1 /\ Z1 ) /\ dom u01) by XBOOLE_1:16
      .= (dom v01 /\ dom u01) /\ Z1 by XBOOLE_1:16;
      dom(v02(#)(x`|Z2) + u02(#)(y`|Z2))
      = dom(v02(#)(x`|Z2)) /\ dom(u02(#)(y`|Z2)) by VALUED_1:def 1
      .= (dom v02 /\ dom(x`|Z2)) /\ dom(u02(#)(y`|Z2)) by VALUED_1:def 4
      .= (dom v02 /\ dom(x`|Z2)) /\ (dom u02 /\ dom (y`|Z2))
      by VALUED_1:def 4;then
A21:  dom(v02(#)(x`|Z2) + u02(#)(y`|Z2))
      = (dom v02 /\ Z2) /\ ( dom u02 /\ dom(y`|Z2)) by A1,FDIFF_1:def 7
      .= (dom v02 /\ Z2) /\ ( dom u02 /\ Z2) by A1,FDIFF_1:def 7
      .= dom v02 /\ (Z2 /\ ( dom u02 /\ Z2)) by XBOOLE_1:16
      .= dom v02 /\ ((Z2 /\ Z2 ) /\ dom u02) by XBOOLE_1:16
      .= (dom v01 /\ dom u01) /\ Z2 by A3,A4,XBOOLE_1:16;
A22:  dom((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB)
      = dom (v01(#)(x`|Z1) + u01(#)(y`|Z1)) /\ AB by RELAT_1:61
      .= (dom v01 /\ dom u01) /\ (Z1 /\ AB) by A20,XBOOLE_1:16
      .= (dom v01 /\ dom u01) /\ AB by A1,XBOOLE_1:28;
A23:  dom((v02(#)(x`|Z2) + u02(#)(y`|Z2)) | AB)
      = dom (v02(#)(x`|Z2) + u02(#)(y`|Z2)) /\ AB by RELAT_1:61
      .= (dom v01 /\ dom u01) /\ (Z2 /\ AB) by A21,XBOOLE_1:16
      .= (dom v01 /\ dom u01) /\ AB by A1,XBOOLE_1:1,28;
      for x0 being object st x0 in dom((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB )
      holds
      ((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB).x0
      = ((v02(#)(x`|Z2) + u02(#)(y`|Z2)) | AB).x0
        proof
          let x0 being object such that
A24:      x0 in dom((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB );
          x0 in dom(v01(#)(x`|Z1) + u01(#)(y`|Z1)) /\ AB by A24,RELAT_1:61;
          then
A25:      x0 in dom(v01(#)(x`|Z1) + u01(#)(y`|Z1)) by XBOOLE_0:def 4;
          then
          x0 in dom(v01(#)(x`|Z1)) /\ dom(u01(#)(y`|Z1)) by VALUED_1:def 1;
          then
A26:      x0 in dom(v01(#)(x`|Z1)) & x0 in dom(u01(#)(y`|Z1))
          by XBOOLE_0:def 4;then
A27:      x0 in dom v01 /\ dom(x`|Z1) & x0 in dom u01 /\ dom(y`|Z1)
          by VALUED_1:def 4;then
          x0 in dom v01 & x0 in dom(x`|Z1)
          & x0 in dom u01 & x0 in dom(y`|Z1) by XBOOLE_0:def 4; then
A28:      x0 in Z1 by A2,FDIFF_1:def 7;
          reconsider x0 as Real by A27;
          ((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB).x0
          = (v01(#)(x`|Z1) + u01(#)(y`|Z1)).x0 by A24,FUNCT_1:47
          .= (v01(#)(x`|Z1)).x0 + (u01(#)(y`|Z1)).x0 by A25,VALUED_1:def 1
          .= v01.x0*(x`|Z1).x0 + (u01(#)(y`|Z1)).x0 by A26,VALUED_1:def 4
          .= v01.x0*(x`|Z1).x0 + u01.x0*(y`|Z1).x0 by A26,VALUED_1:def 4
          .= v01.x0*diff(x,x0) + u01.x0*(y`|Z1).x0
          by A2,A28,FDIFF_1:def 7; then
A29:      ((v01(#)(x`|Z1) + u01(#)(y`|Z1)) | AB).x0
          = v01.x0*diff(x,x0) + u01.x0*diff(y,x0)
          by A2,A28,FDIFF_1:def 7;
          x0 in dom(v02(#)(x`|Z2) + u02(#)(y`|Z2)) /\ AB
          by A22,A23,A24,RELAT_1:61; then
A30:      x0 in dom(v02(#)(x`|Z2) + u02(#)(y`|Z2)) by XBOOLE_0:def 4;
          then
          x0 in dom(v02(#)(x`|Z2)) /\ dom(u02(#)(y`|Z2)) by VALUED_1:def 1;
          then
A31:      x0 in dom(v02(#)(x`|Z2)) & x0 in dom(u02(#)(y`|Z2))
          by XBOOLE_0:def 4;then
          x0 in dom v02 /\ dom(x`|Z2) & x0 in dom u02 /\ dom(y`|Z2)
          by VALUED_1:def 4;then
          x0 in dom v02 & x0 in dom(x`|Z2)
          & x0 in dom u02 & x0 in dom(y`|Z2) by XBOOLE_0:def 4;then
A32:      x0 in Z2 by A1,FDIFF_1:def 7;
          ((v02(#)(x`|Z2) + u02(#)(y`|Z2)) | AB ).x0
          = (v02(#)(x`|Z2) + u02(#)(y`|Z2)).x0 by A22,A23,A24,FUNCT_1:47
          .= (v02(#)(x`|Z2)).x0 + (u02(#)(y`|Z2)).x0 by A30,VALUED_1:def 1
          .= v02.x0*(x`|Z2).x0 + (u02(#)(y`|Z2)).x0 by A31,VALUED_1:def 4
          .= v02.x0*(x`|Z2).x0 + u02.x0*(y`|Z2).x0 by A31,VALUED_1:def 4
          .= v02.x0*diff(x,x0) + u02.x0*(y`|Z2).x0
          by A1,A32,FDIFF_1:def 7;
          hence thesis by A1,A3,A4,A29,A32,FDIFF_1:def 7;
        end;
      hence thesis by A22,A23,FUNCT_1:def 11;
    end;
   integral( v01(#)(x`|Z1) + u01(#)(y`|Z1),a,b)
   = integral( v01(#)(x`|Z1) + u01(#)(y`|Z1),AB) by INTEGRA5:19
  .= integral( (v02(#)(x`|Z2) + u02(#)(y`|Z2)),AB) by A19
  .=integral( v02(#)(x`|Z2) + u02(#)(y`|Z2) ,a,b) by INTEGRA5:19;
  hence thesis by A3,A4,A18;
end;

Lm2: for a,b be Real, x1,y1,x2,y2 be PartFunc of REAL,REAL,
Z be Subset of REAL,
f be PartFunc of COMPLEX,COMPLEX st
a <= b &
[.a,b.] c= dom x1 & [.a,b.] c= dom y1 &
[.a,b.] c= dom x2 & [.a,b.] c= dom y2 &
x1| [.a,b.] = x2| [.a,b.] & y1| [.a,b.] = y2| [.a,b.] & Z is open &
[.a,b.] c= Z & x1 is_differentiable_on Z & y1 is_differentiable_on Z &
rng ( (x1 + <i>(#)y1) | [.a,b.] ) c=dom f &
x2 is_differentiable_on Z & y2 is_differentiable_on Z &
rng ( (x2 + <i>(#)y2) | [.a,b.] ) c=dom f
holds
integral(f,x1,y1,a,b,Z) = integral(f,x2,y2,a,b,Z)
proof
  let a,b be Real,
  x1,y1,x2,y2 be PartFunc of REAL,REAL,
  Z be Subset of REAL,
  f be PartFunc of COMPLEX, COMPLEX;
  assume
A1: a <= b & [.a,b.] c= dom x1 & [.a,b.] c= dom y1 &
  [.a,b.] c= dom x2 & [.a,b.] c= dom y2 &
  x1| [.a,b.] = x2| [.a,b.] & y1| [.a,b.] = y2| [.a,b.] &
  Z is open & [.a,b.] c= Z & x1 is_differentiable_on Z &
  y1 is_differentiable_on Z &
  rng ( (x1 + <i>(#)y1) | [.a,b.] ) c= dom f &
  x2 is_differentiable_on Z & y2 is_differentiable_on Z &
  rng ( (x2 + <i>(#)y2) | [.a,b.] ) c=dom f;
  consider u01, v01 be PartFunc of REAL,REAL such that
A2: u01=(Re f)* (R2-to-C) *<:x1,y1:> & v01=(Im f)* (R2-to-C) *<:x1,y1:> &
  integral(f,x1,y1,a,b,Z)= integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,a,b )
  + integral( v01(#)(x1`|Z) + u01(#)(y1`|Z) ,a,b )*<i> by Def2;
  consider u02,v02 be PartFunc of REAL,REAL such that
A3: u02=(Re f)* (R2-to-C) *<:x2,y2:> & v02=(Im f)* (R2-to-C) *<:x2,y2:> &
  integral(f,x2,y2,a,b,Z)= integral( u02(#)(x2`|Z) - v02(#)(y2`|Z) ,a,b )
  + integral( v02(#)(x2`|Z) + u02(#)(y2`|Z) ,a,b )*<i> by Def2;
  reconsider AB=[.a,b.] as non empty closed_interval Subset of REAL
  by A1,MEASURE5:14;
A4: now assume
A5: not (a = b or a < b);then
    0 < b - a or 0 < a - b by XREAL_1:55;then
    a < a + (b -a) or 0 < a - b by XREAL_1:29;then
    a < b or b < b + (a - b) by XREAL_1:29;
    hence contradiction by A5,A1;
  end;
  per cases by A4;
  suppose
A6: a < b;
A7: u01 | AB = u02 | AB
    proof
A8:   dom(u01 | AB) = dom(u02 | AB)
      proof
A9:     for x0 be object st x0 in dom(u01 | AB) holds x0 in dom(u02 | AB)
        proof
          let x0 be object such that
A10:      x0 in dom(u01 | AB);
          x0 in dom u01 /\ AB by A10,RELAT_1:61;then
A11:      x0 in dom u01 & x0 in AB by XBOOLE_0:def 4;then
          x0 in dom <:x1,y1:> & <:x1,y1:>.x0 in dom((Re f)* (R2-to-C))
          & x0 in AB by A2,FUNCT_1:11;then
          x0 in AB &
          [x1.x0,y1.x0] in dom((Re f)* (R2-to-C)) by FUNCT_3:def 7; then
          x0 in AB &
          [(x1 | AB).x0,y1.x0] in dom((Re f)* (R2-to-C)) by FUNCT_1:49;
          then
          x0 in AB & [(x2 | AB).x0,(y2 | AB).x0] in dom((Re f)* (R2-to-C))
          by A1,FUNCT_1:49;then
          x0 in AB & [(x2 | AB).x0,y2.x0] in dom((Re f)* (R2-to-C))
          by FUNCT_1:49; then
A12:      x0 in AB & [x2.x0,y2.x0] in dom((Re f)* (R2-to-C)) by FUNCT_1:49;
          x0 in dom x2 /\ dom y2 by A1,A11,XBOOLE_0:def 4;then
          x0 in dom <:x2,y2:> by FUNCT_3:def 7;then
          x0 in AB & x0 in dom <:x2,y2:>
          & <:x2,y2:>.x0 in dom((Re f)* (R2-to-C))
          by A12,FUNCT_3:def 7;then
          x0 in AB & x0 in dom u02 by A3,FUNCT_1:11;then
          x0 in dom u02 /\ AB by XBOOLE_0:def 4;
          hence thesis by RELAT_1:61;
        end;
        for x0 be object st x0 in dom(u02 | AB) holds x0 in dom(u01 | AB)
        proof
          let x0 be object such that
A13:      x0 in dom(u02 | AB);
          x0 in dom u02 /\ AB by A13,RELAT_1:61;then
A14:      x0 in dom u02 & x0 in AB by XBOOLE_0:def 4;then
          x0 in dom <:x2,y2:> & <:x2,y2:>.x0 in dom((Re f)* (R2-to-C))
          & x0 in AB by A3,FUNCT_1:11;then
          x0 in AB & [x2.x0,y2.x0] in dom((Re f)* (R2-to-C)) by FUNCT_3:def 7;
          then
          x0 in AB &
          [(x2 | AB).x0,y2.x0] in dom((Re f)* (R2-to-C)) by FUNCT_1:49;
          then
          x0 in AB & [(x1 | AB).x0,(y1 | AB).x0] in dom((Re f)* (R2-to-C))
          by A1,FUNCT_1:49;then
          x0 in AB & [(x1 | AB).x0,y1.x0] in dom((Re f)* (R2-to-C))
          by FUNCT_1:49;then
A15:      x0 in AB & [x1.x0,y1.x0] in dom((Re f)* (R2-to-C)) by FUNCT_1:49;
          x0 in dom x1 /\ dom y1 by A1,A14,XBOOLE_0:def 4;then
          x0 in dom <:x1,y1:> by FUNCT_3:def 7;then
          x0 in AB & x0 in dom <:x1,y1:> &
          <:x1,y1:>.x0 in dom((Re f)* (R2-to-C))
          by A15,FUNCT_3:def 7;then
          x0 in AB & x0 in dom u01 by A2,FUNCT_1:11;then
          x0 in dom u01 /\ AB by XBOOLE_0:def 4;
          hence thesis by RELAT_1:61;
        end;
        hence thesis by A9,TARSKI:2;
      end;
      for x0 be object st x0 in dom(u01 | AB)
holds (u01 | AB).x0 = (u02 | AB).x0
      proof
        let x0 be object such that
A16:    x0 in dom(u01 | AB);
        x0 in dom u01 /\ AB by A16,RELAT_1:61;
        then
A17:    x0 in AB & x0 in dom u01 by XBOOLE_0:def 4;
        then reconsider x0 as Real;
A18:    AB c= dom x1 /\ dom y1 by A1,XBOOLE_1:19;then
        x0 in dom x1 /\ dom y1 by A17;then
        x0 in dom (<:x1,y1:>) by FUNCT_3:def 7;then
A19:    u01.x0 = ((Re f)*(R2-to-C)).(<:x1,y1:>.x0) by A2,FUNCT_1:13;
A20:    AB c= dom x2 /\ dom y2 by A1,XBOOLE_1:19;then
        x0 in dom x2 /\ dom y2 by A17;then
        x0 in dom (<:x2,y2:>) by FUNCT_3:def 7;then
        u02.x0 = ((Re f)*(R2-to-C)).(<:x2,y2:>.x0) by A3,FUNCT_1:13;
        then
A21:    u02.x0 = ((Re f)*(R2-to-C)).([x2.x0,y2.x0]) by A17,A20,FUNCT_3:48;
A22:    x1.x0 = (x1| [.a,b.]).x0 by A17,FUNCT_1:49
        .= x2.x0 by A17,A1,FUNCT_1:49;
A23:    y1.x0 = (y1| [.a,b.]).x0 by A17,FUNCT_1:49
        .= y2.x0 by A17,A1,FUNCT_1:49;
        u01.x0 = (u01 | AB).x0 & u02.x0 = (u02 | AB).x0 by A17,FUNCT_1:49;
        hence thesis by A17,A18,A19,A21,A22,A23,FUNCT_3:48;
      end;
      hence thesis by A8,FUNCT_1:def 11;
    end;
A24: (x1`|Z)| AB = (x2`|Z)| AB
    proof
A25:  dom ((x1`|Z)| AB) = dom (x1`|Z) /\ AB by RELAT_1:61
      .= Z /\ AB by A1,FDIFF_1:def 7
      .= AB by A1,XBOOLE_1:28;
A26:  dom ((x2`|Z)| AB) = dom (x2`|Z) /\ AB by RELAT_1:61
      .= Z /\ AB by A1,FDIFF_1:def 7
      .= AB by A1,XBOOLE_1:28;
      for x0 be object st x0 in dom((x1`|Z)| AB) holds
      ((x1`|Z)| AB).x0 = ((x2`|Z)| AB).x0
      proof
        let x0 be object such that
A27:    x0 in dom((x1`|Z)| AB);
        x0 in dom(x1`|Z) by A27,RELAT_1:57;
        then reconsider x0 as Real;
A28:    ((x2`|Z)| AB).x0 = (x2`|Z).x0 by A27,FUNCT_1:49;
A29:    (x1`|Z).x0 = diff(x1,x0) by A1,A25,A27,FDIFF_1:def 7;
A30:    (x2`|Z).x0 = diff(x2,x0) by A1,A25,A27,FDIFF_1:def 7;
A31:    now assume
A32:      not (x0 in ].a,b.[ or x0 = a or x0 = b);
          x0 in {r where r is Real: a <= r & r <= b}
          by A25,A27,RCOMP_1:def 1;then
A33:      ex r be Real st r = x0 & a <= r & r <= b;
A34:      now assume
A35:        not (a = x0 or a < x0);then
            0 < x0 - a or 0 < a - x0 by XREAL_1:55;then
            a < a + (x0 -a) or 0 < a - x0 by XREAL_1:29;then
            a < x0 or x0 < x0 + (a - x0) by XREAL_1:29;
            hence contradiction by A33,A35;
          end;
A36:      now assume
A37:        not (x0 = b or x0 < b);then
            0 < x0 - b or 0 < b - x0 by XREAL_1:55;then
            b < b + (x0 -b) or 0 < b - x0 by XREAL_1:29;then
            b < x0 or x0 < x0 + (b - x0) by XREAL_1:29;
            hence contradiction by A33,A37;
          end;
          not (x0 in {q where q is Real: a<q & q<b})
by A32,RCOMP_1:def 2;
          hence contradiction by A32,A34,A36;
        end;
        diff(x1,x0) = diff(x2,x0)
        proof
          per cases by A31;
          suppose
A38:        x0 = a;
            then x0 in {r where r is Real: a <= r & r <= b} by A1;then
A39:        x0 in [.a,b.] by RCOMP_1:def 1;then
A40:        x1 is_differentiable_in x0 by A1,FDIFF_1:9;then
A41:        x1 is_right_differentiable_in x0 &
            diff(x1,x0) = Rdiff(x1,x0) by FDIFF_3:22;
            x2 is_differentiable_in x0 by A1,A39,FDIFF_1:9;then
A42:        x2 is_right_differentiable_in x0 &
            diff(x2,x0) = Rdiff(x2,x0) by FDIFF_3:22;
then A43:        x1 - x2 is_right_differentiable_in x0 by A41,FDIFF_3:17;
            Rdiff(x1,x0) = Rdiff(x2,x0)
            proof
A44:          Rdiff(x1,x0) - Rdiff(x2,x0) = Rdiff(x1-x2,x0)
              by A41,A42,FDIFF_3:17;
              for h,c1 st rng c1 = {x0} & rng (h+c1) c= dom (x1-x2) &
              (for n being Nat holds h.n > 0) holds
              lim (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)) = 0
              proof
                let h,c1 such that
A45:            rng c1 = {x0} & rng (h+c1) c= dom (x1-x2) &
                (for n being Nat holds h.n > 0);
A46:            h is convergent & lim h = 0;
A47:            0 < b - x0 by A6,A38,XREAL_1:50;
                then consider n being Nat such that
A48:            for m being Nat st n<=m holds |.h.m - 0 .| < (b - x0)/2
                by A46,SEQ_2:def 7;
A49:            for p1 st 0<p1 ex n1 being Nat st
                 for m being Nat st n1 <= m holds
                |.(h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m-0 .| < p1
                proof
                  let p1 such that
A50:              0 < p1;
                  take n;
                  for m being Nat st n <= m holds
                  (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m = 0
                  proof
                    let m be Nat such that
A51:                n <= m;
A52:                 m in NAT by ORDINAL1:def 12;
A53:                |.h.m - 0 .| < (b - x0)/2 by A48,A51;
A54:                0 < h.m by A45;then
A55:                h.m < (b - x0)/2 by A53,ABSVALUE:def 1;
A56:                a + 0 <= x0 + h.m by A38,A54,XREAL_1:7;
                    x0 + h.m <= x0 + (b - x0)/2 by A55,XREAL_1:7;then
A57:                x0 + h.m + 0 <= b - (b - x0)/2 + (b - x0)/2
                    by A47,XREAL_1:7;
A58:                [.a,b.] c= dom x1 /\ dom x2 by A1,XBOOLE_1:19;then
                    x0 in dom x1 /\ dom x2 by A39;then
A59:                x0 in dom(x1-x2) by VALUED_1:12;
A60:                [.a,b.] c= dom(x1-x2) by A58,VALUED_1:12;
                    x0 + h.m in {r where r is Real : a <= r & r <= b }
                    by A56,A57;then
A61:                x0 + h.m in [.a,b.] by RCOMP_1:def 1;
A62:                x0 in rng c1 by A45,TARSKI:def 1;
A63:                lim c1 = c1.m by SEQ_4:26;
A64:                (h+c1).m = h.m + c1.m by SEQ_1:7
                    .= h.m + x0 by A62,A63,SEQ_4:25;
A65:                rng c1 c= dom (x1-x2)
                    by A45,A59,TARSKI:def 1;
A66:                (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m
                    = (h").m*((x1-x2)/*(h+c1) - (x1-x2)/*c1).m by SEQ_1:8
                    .= (h").m*(((x1-x2)/*(h+c1)).m - ((x1-x2)/*c1).m )
                    by RFUNCT_2:1
                    .= (h").m*((x1-x2).((h+c1).m) - ((x1-x2)/*c1).m )
                    by A45,FUNCT_2:108,A52
                    .= (h").m*((x1-x2).((h+c1).m) - (x1-x2).(c1.m) )
                    by A65,FUNCT_2:108,A52
                    .= (h").m*((x1-x2).(h.m+x0) - (x1-x2).x0 )
                    by A62,A63,A64,SEQ_4:25;
A67:                (x1-x2).(h.m+x0) = x1.(h.m+x0) - x2.(h.m+x0)
                    by A60,A61,VALUED_1:13
                    .= (x1 | [.a,b.]).(h.m+x0) - x2.(h.m+x0)
                    by A61,FUNCT_1:49
                    .= (x1 | [.a,b.]).(h.m+x0) - (x2 | [.a,b.]).(h.m+x0)
                    by A61,FUNCT_1:49
                    .= 0 by A1;
                    (x1-x2).x0 = x1.x0 - x2.x0 by A59,VALUED_1:13
                    .= (x1 | [.a,b.]).x0 - x2.x0 by A39,FUNCT_1:49
                    .= (x1 | [.a,b.]).x0 - (x2 | [.a,b.]).x0
                    by A39,FUNCT_1:49
                    .= 0 by A1;
                    hence thesis by A66,A67;
                  end;
                  hence thesis by A50,COMPLEX1:44;
                end;
                then (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1))
                is convergent by SEQ_2:def 6;
                hence thesis by A49,SEQ_2:def 7;
              end;then
              Rdiff(x1,x0) - Rdiff(x2,x0) = 0 by A43,A44,FDIFF_3:def 6;
              hence thesis;
            end;
            hence thesis by A40,A42,FDIFF_3:22;
          end;
          suppose
A68:        x0 in ].a,b.[;
A69:        ].a,b.[ is open by RCOMP_1:7;
A70:        ].a,b.[ c= [.a,b.]
            proof
              for x0 be object st x0 in ].a,b.[ holds x0 in [.a,b.]
              proof
                let x0 be object such that
A71:            x0 in ].a,b.[;
                x0 in {r where r is Real : a < r & r < b }
                by A71,RCOMP_1:def 2;then
A72:            ex r st r=x0 & a < r & r < b;then
                reconsider x0 as Real;
                x0 in {r where r is Real : a <= r & r <= b } by A72;
                hence thesis by RCOMP_1:def 1;
              end;
              hence thesis;
            end;then
A73:        x1 is_differentiable_on ].a,b.[
            by A1,A69,FDIFF_1:26,XBOOLE_1:1; then
A74:        x1| (].a,b.[) is_differentiable_on ].a,b.[ &
            (x1| (].a,b.[))`| (].a,b.[) = x1`| (].a,b.[) by FDIFF_2:16;
A75:        (x1`| (].a,b.[)).x0 = diff(x1,x0) by A68,A73,FDIFF_1:def 7;
A76:        x2 is_differentiable_on ].a,b.[
            by A69,A70,A1,FDIFF_1:26,XBOOLE_1:1;
            then
A77:        x2| (].a,b.[) is_differentiable_on ].a,b.[ &
            (x2| (].a,b.[))`| (].a,b.[) = x2`| (].a,b.[) by FDIFF_2:16;
A78:        (x2`| (].a,b.[)).x0 = diff(x2,x0) by A68,A76,FDIFF_1:def 7;
A79:        dom (x1| (].a,b.[) ) = dom x1 /\ (].a,b.[) by RELAT_1:61
            .= ].a,b.[ by A1,A70,XBOOLE_1:1,28
            .= dom x2 /\ (].a,b.[) by A1,A70,XBOOLE_1:1,28
            .= dom (x2| (].a,b.[) ) by RELAT_1:61;
            for x0 be object st x0 in dom (x1| (].a,b.[) ) holds
            (x1| (].a,b.[) ).x0 = (x2| (].a,b.[) ).x0
            proof
              let x0 be object such that
A80:          x0 in dom (x1| (].a,b.[) );
A81:          dom (x1| (].a,b.[) ) = dom x1 /\ (].a,b.[) by RELAT_1:61
              .= ].a,b.[ by A1,A70,XBOOLE_1:1,28;
              then (x1| (].a,b.[) ).x0 = x1.x0 by A80,FUNCT_1:49
              .= (x1| ([.a,b.]) ).x0 by A70,A80,A81,FUNCT_1:49
              .= x2.x0 by A70,A80,A81,A1,FUNCT_1:49
              .=(x2| (].a,b.[) ).x0 by A80,A81,FUNCT_1:49;
              hence thesis;
            end;
            hence thesis by A74,A75,A77,A78,A79,FUNCT_1:2;
          end;
          suppose
A82:        x0 = b;
            then x0 in {r where r is Real: a<=r & r<=b} by A1;then
A83:        x0 in [.a,b.] by RCOMP_1:def 1;then
A84:        x1 is_differentiable_in x0 by A1,FDIFF_1:9;then
A85:        x1 is_left_differentiable_in x0 &
            diff(x1,x0) = Ldiff(x1,x0) by FDIFF_3:22;
            x2 is_differentiable_in x0 by A1,A83,FDIFF_1:9;then
A86:        x2 is_left_differentiable_in x0 &
            diff(x2,x0) = Ldiff(x2,x0) by FDIFF_3:22;
then A87:        x1 - x2 is_left_differentiable_in x0 by A85,FDIFF_3:11;
            Ldiff(x1,x0) = Ldiff(x2,x0)
            proof
A88:          Ldiff(x1,x0) - Ldiff(x2,x0) = Ldiff(x1-x2,x0)
              by A85,A86,FDIFF_3:11;
              for h,c1 st rng c1 = {x0} & rng (h+c1) c= dom (x1-x2) &
              (for n being Nat holds h.n < 0) holds
              lim (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)) = 0
              proof
                let h,c1 such that
A89:            rng c1 = {x0} & rng (h+c1) c= dom (x1-x2) &
                (for n being Nat holds h.n < 0);
A90:            h is convergent & lim h = 0;
A91:            0 < b - a by A6,XREAL_1:50;
                then consider n being Nat such that
A92:            for m being Nat st n<=m holds |.h.m - 0 .| < (x0 - a)/2
                by A82,A90,SEQ_2:def 7;
A93:            for p1 st 0<p1
                  ex n1 being Nat st for m being Nat st n1 <= m holds
                |.(h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m-0 .| < p1
                proof
                  let p1 such that
A94:              0 < p1;
                  take n;
                  for m being Nat st n <= m holds
                  (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m = 0
                  proof
                    let m being Nat such that
A95:                n <= m;
A96:                 m in NAT by ORDINAL1:def 12;
A97:                |.h.m - 0 .| < (x0 - a)/2 by A92,A95;
A98:                h.m < 0 by A89;then
A99:                -h.m < (x0 - a)/2 by A97,ABSVALUE:def 1;
A100:                x0 + h.m <= b + 0 by A82,A98,XREAL_1:7;
                    x0 - (x0 - a)/2 <= x0 - (-h.m) by A99,XREAL_1:13;then
A101:               a + (x0 - a)/2 - (x0 - a)/2 <= x0 + h.m - 0
                    by A82,A91,XREAL_1:13;
A102:               [.a,b.] c= dom x1 /\ dom x2 by A1,XBOOLE_1:19;then
                    x0 in dom x1 /\ dom x2 by A83;then
A103:               x0 in dom(x1-x2) by VALUED_1:12;
A104:               [.a,b.] c= dom(x1-x2) by A102,VALUED_1:12;
                    x0 + h.m in {r where r is Real: a <= r & r <= b }
                    by A100,A101;then
A105:               x0 + h.m in [.a,b.] by RCOMP_1:def 1;
                    x0 in rng c1 by A89,TARSKI:def 1;then
A106:               lim c1 = x0 by SEQ_4:25;
A107:               (h+c1).m = h.m + c1.m by SEQ_1:7
                    .= h.m + x0 by A106,SEQ_4:26;
A108:               rng c1 c= dom (x1-x2)
                    by A89,A103,TARSKI:def 1;
A109:               (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1)).m
                    = (h").m*((x1-x2)/*(h+c1) - (x1-x2)/*c1).m
                    by SEQ_1:8
                    .= (h").m*(((x1-x2)/*(h+c1)).m - ((x1-x2)/*c1).m )
                    by RFUNCT_2:1
                    .= (h").m*((x1-x2).((h+c1).m) - ((x1-x2)/*c1).m )
                    by A89,FUNCT_2:108,A96
                    .= (h").m*((x1-x2).((h+c1).m) - (x1-x2).(c1.m) )
                    by A108,FUNCT_2:108,A96
                    .= (h").m*((x1-x2).(h.m+x0) - (x1-x2).x0 )
                    by A106,A107,SEQ_4:26;
A110:               (x1-x2).(h.m+x0)
                    = x1.(h.m+x0) - x2.(h.m+x0) by A104,A105,VALUED_1:13
                    .= (x1 | [.a,b.]).(h.m+x0) - x2.(h.m+x0)
                    by A105,FUNCT_1:49
                    .= (x1 | [.a,b.]).(h.m+x0) - (x2 | [.a,b.]).(h.m+x0)
                    by A105,FUNCT_1:49
                    .= 0 by A1;
                    (x1-x2).x0 = x1.x0 - x2.x0 by A103,VALUED_1:13
                    .= (x1 | [.a,b.]).x0 -  x2.x0 by A83,FUNCT_1:49
                    .= (x1 | [.a,b.]).x0 -  (x2 | [.a,b.]).x0
                    by A83,FUNCT_1:49
                    .= 0 by A1;
                    hence thesis by A109,A110;
                  end;
                  hence thesis by A94,COMPLEX1:44;
                end; then
                (h"(#)((x1-x2)/*(h+c1) - (x1-x2)/*c1))
                is convergent by SEQ_2:def 6;
                hence thesis by A93,SEQ_2:def 7;
              end;then
              Ldiff(x1-x2,x0) = 0 by A87,FDIFF_3:def 5;
              hence thesis by A88;
            end;
            hence thesis by A84,A86,FDIFF_3:22;
          end;
        end;
        hence thesis by A27,A28,A29,A30,FUNCT_1:49;
      end;
      hence thesis by A25,A26,FUNCT_1:def 11;
    end;
A111: v01 | AB = v02 | AB
    proof
A112: dom(v01 | AB) = dom(v02 | AB)
      proof
A113:   for x0 be object st x0 in dom(v01 | AB) holds x0 in dom(v02 | AB)
        proof
          let x0 be object such that
A114:     x0 in dom(v01 | AB);
          x0 in dom v01 /\ AB by A114,RELAT_1:61;then
A115:     x0 in dom v01 & x0 in AB by XBOOLE_0:def 4;then
          x0 in dom <:x1,y1:> & <:x1,y1:>.x0 in dom((Im f)* (R2-to-C)) &
          x0 in AB by A2,FUNCT_1:11;then
          x0 in AB &
          [x1.x0,y1.x0] in dom((Im f)* (R2-to-C)) by FUNCT_3:def 7;then
          x0 in AB &
          [(x1 | AB).x0,y1.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          then
          x0 in AB & [(x2 | AB).x0,(y2 | AB).x0] in dom((Im f)* (R2-to-C))
          by A1,FUNCT_1:49;then
          x0 in AB &
          [(x2 | AB).x0,y2.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          then
A116:     x0 in AB & [x2.x0,y2.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          x0 in dom x2 /\ dom y2 by A1,A115,XBOOLE_0:def 4;then
          x0 in dom <:x2,y2:> by FUNCT_3:def 7;then
          x0 in AB & x0 in dom <:x2,y2:> &
          <:x2,y2:>.x0 in dom((Im f)* (R2-to-C))
          by A116,FUNCT_3:def 7;then
          x0 in AB & x0 in dom v02 by A3,FUNCT_1:11;then
          x0 in dom v02 /\ AB by XBOOLE_0:def 4;
          hence thesis by RELAT_1:61;
        end;
        for x0 be object st x0 in dom(v02 | AB) holds x0 in dom(v01 | AB)
        proof
          let x0 be object such that
A117:     x0 in dom(v02 | AB);
          x0 in dom v02 /\ AB by A117,RELAT_1:61;then
A118:     x0 in dom v02 & x0 in AB by XBOOLE_0:def 4;then
          x0 in dom <:x2,y2:> & <:x2,y2:>.x0 in dom((Im f)* (R2-to-C)) &
          x0 in AB by A3,FUNCT_1:11;then
          x0 in AB &
          [x2.x0,y2.x0] in dom((Im f)* (R2-to-C)) by FUNCT_3:def 7;then
          x0 in AB &
          [(x2 | AB).x0,y2.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          then x0 in AB & [(x1 | AB).x0,(y1 | AB).x0] in dom((Im f)* (R2-to-C))
          by A1,FUNCT_1:49;then
          x0 in AB &
          [(x1 | AB).x0,y1.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          then
A119:     x0 in AB & [x1.x0,y1.x0] in dom((Im f)* (R2-to-C)) by FUNCT_1:49;
          x0 in dom x1 /\ dom y1 by A1,A118,XBOOLE_0:def 4;then
          x0 in dom <:x1,y1:> by FUNCT_3:def 7;then
          x0 in AB & x0 in dom <:x1,y1:> &
          <:x1,y1:>.x0 in dom((Im f)* (R2-to-C))
          by A119,FUNCT_3:def 7;then
          x0 in AB & x0 in dom v01 by A2,FUNCT_1:11;then
          x0 in dom v01 /\ AB by XBOOLE_0:def 4;
          hence thesis by RELAT_1:61;
        end;
        hence thesis by A113,TARSKI:2;
      end;
      for x0 be object st x0 in dom(v01 | AB)
holds (v01 | AB).x0 = (v02 | AB).x0
      proof
        let x0 be object such that
A120:   x0 in dom(v01 | AB);
        x0 in dom v01 /\ AB by A120,RELAT_1:61;
        then
A121:   x0 in AB & x0 in dom v01 by XBOOLE_0:def 4;
        then reconsider x0 as Real;
A122:   AB c= dom x1 /\ dom y1 by A1,XBOOLE_1:19;then
        x0 in dom x1 /\ dom y1 by A121;then
        x0 in dom (<:x1,y1:>) by FUNCT_3:def 7;then
A123:   v01.x0 = ((Im f)*(R2-to-C)).(<:x1,y1:>.x0) by A2,FUNCT_1:13;
A124:   AB c= dom x2 /\ dom y2 by A1,XBOOLE_1:19;then
        x0 in dom x2 /\ dom y2 by A121;then
        x0 in dom (<:x2,y2:>) by FUNCT_3:def 7;then
        v02.x0 = ((Im f)*(R2-to-C)).(<:x2,y2:>.x0) by A3,FUNCT_1:13;then
A125:   v02.x0 = ((Im f)*(R2-to-C)).([x2.x0,y2.x0]) by A121,A124,FUNCT_3:48;
A126:   x1.x0 = (x1| [.a,b.]).x0 by A121,FUNCT_1:49
        .= x2.x0 by A121,A1,FUNCT_1:49;
A127:   y1.x0 = (y1| [.a,b.]).x0 by A121,FUNCT_1:49
        .= y2.x0 by A121,A1,FUNCT_1:49;
        v01.x0 = (v01 | AB).x0 & v02.x0 = (v02 | AB).x0 by A121,FUNCT_1:49;
        hence thesis by A126,A127,A123,A121,A122,A125,FUNCT_3:48;
      end;
      hence thesis by A112,FUNCT_1:def 11;
    end;
A128: (y1`|Z)| AB = (y2`|Z)| AB
    proof
A129: dom ((y1`|Z)| AB) = dom (y1`|Z) /\ AB by RELAT_1:61
      .= Z /\ AB by A1,FDIFF_1:def 7
      .= AB by A1,XBOOLE_1:28;
A130: dom ((y2`|Z)| AB) = dom (y2`|Z) /\ AB by RELAT_1:61
      .= Z /\ AB by A1,FDIFF_1:def 7
      .= AB by A1,XBOOLE_1:28;
      for x0 be object st x0 in dom((y1`|Z)| AB) holds
      ((y1`|Z)| AB).x0 = ((y2`|Z)| AB).x0
      proof
        let x0 be object such that
A131:   x0 in dom((y1`|Z)| AB);
        x0 in dom(y1`|Z) by A131,RELAT_1:57;
        then reconsider x0 as Real;
A132:   ((y2`|Z)| AB).x0 = (y2`|Z).x0 by A131,FUNCT_1:49;
A133:   (y1`|Z).x0 = diff(y1,x0) by A1,A131,A129,FDIFF_1:def 7;
A134:   (y2`|Z).x0 = diff(y2,x0) by A1,A131,A129,FDIFF_1:def 7;
A135:   now assume
A136:     not (x0 in ].a,b.[ or x0 = a or x0 = b);
          x0 in {r where r is Real: a <= r & r <= b}
          by A129,A131,RCOMP_1:def 1;then
A137:     ex r be Real st r=x0 & a<=r & r<=b;
A138:     now assume
A139:       not (a = x0 or a < x0);then
            0 < x0 - a or 0 < a - x0 by XREAL_1:55;then
            a < a + (x0 -a) or 0 < a - x0 by XREAL_1:29;then
            a < x0 or x0 < x0 + (a - x0) by XREAL_1:29;
            hence contradiction by A137,A139;
          end;
A140:     now assume
A141:       not (x0 = b or x0 < b);then
            0 < x0 - b or 0 < b - x0 by XREAL_1:55;then
            b < b + (x0 -b) or 0 < b - x0 by XREAL_1:29;then
            b < x0 or x0 < x0 + (b - x0) by XREAL_1:29;
            hence contradiction by A137,A141;
          end;
          not (x0 in {q where q is Real: a<q & q<b})
by A136,RCOMP_1:def 2;
          hence contradiction by A136,A138,A140;
        end;
        diff(y1,x0) = diff(y2,x0)
        proof
          per cases by A135;
          suppose
A142:       x0 = a;
            then x0 in {r where r is Real: a <= r & r <= b} by A1;then
A143:       x0 in [.a,b.] by RCOMP_1:def 1;then
A144:       y1 is_differentiable_in x0 by A1,FDIFF_1:9;then
A145:       y1 is_right_differentiable_in x0 &
            diff(y1,x0) = Rdiff(y1,x0) by FDIFF_3:22;
            y2 is_differentiable_in x0 by A1,A143,FDIFF_1:9;then
A146:       y2 is_right_differentiable_in x0 &
            diff(y2,x0) = Rdiff(y2,x0) by FDIFF_3:22;
then A147:       y1 - y2 is_right_differentiable_in x0 by A145,FDIFF_3:17;
            Rdiff(y1,x0) = Rdiff(y2,x0)
            proof
A148:         Rdiff(y1,x0) - Rdiff(y2,x0) = Rdiff(y1-y2,x0)
              by A145,A146,FDIFF_3:17;
              for h,c1 st rng c1 = {x0} & rng (h+c1) c= dom (y1-y2) &
              (for n being Nat holds h.n > 0) holds
              lim (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)) = 0
              proof
                let h,c1 such that
A149:           rng c1 = {x0} & rng (h+c1) c= dom (y1-y2) &
                (for n being Nat holds h.n > 0);
A150:           h is convergent & lim h = 0;
A151:           0 < b - x0 by A6,A142,XREAL_1:50;
                then consider n being Nat such that
A152:           for m being Nat st n<=m holds |.h.m - 0 .| < (b - x0)/2
                by A150,SEQ_2:def 7;
A153:           for p1 st 0 < p1
                 ex n1 being Nat st for m being Nat st n1 <= m holds
                |.(h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m-0 .|<p1
                proof
                  let p1 such that
A154:             0 < p1;
                  take n;
                  for m being Nat st n <= m holds
                  (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m = 0
                  proof
                    let m be Nat such that
A155:               n <= m;
A156:               |.h.m - 0 .| < (b - x0)/2 by A152,A155;
A157:                 m in NAT by ORDINAL1:def 12;
A158:               0 < h.m by A149;then
A159:               h.m < (b - x0)/2 by A156,ABSVALUE:def 1;
A160:               a + 0 <= x0 + h.m by A142,A158,XREAL_1:7;
                    x0 + h.m <= x0 + (b - x0)/2 by A159,XREAL_1:7;then
A161:               x0 + h.m + 0 <= b - (b - x0)/2 + (b - x0)/2
                    by A151,XREAL_1:7;
A162:               [.a,b.] c= dom y1 /\ dom y2 by A1,XBOOLE_1:19;then
                    x0 in dom y1 /\ dom y2 by A143;then
A163:               x0 in dom(y1-y2) by VALUED_1:12;
A164:               [.a,b.] c= dom(y1-y2) by A162,VALUED_1:12;
                    x0 + h.m in {r where r is Real : a <= r & r <= b }
                    by A160,A161;then
A165:               x0 + h.m in [.a,b.] by RCOMP_1:def 1;
A166:               x0 in rng c1 by A149,TARSKI:def 1;
A167:               lim c1 = c1.m by SEQ_4:26;
A168:               (h+c1).m = h.m + c1.m by SEQ_1:7
                    .= h.m + x0 by A167,A166,SEQ_4:25;
A169:               rng c1 c= dom (y1-y2)
                    by A163,A149,TARSKI:def 1;
A170:               (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m
                    = (h").m*((y1-y2)/*(h+c1) - (y1-y2)/*c1).m
                    by SEQ_1:8
                    .= (h").m*(((y1-y2)/*(h+c1)).m - ((y1-y2)/*c1).m )
                    by RFUNCT_2:1
                    .= (h").m*((y1-y2).((h+c1).m) - ((y1-y2)/*c1).m )
                    by A149,FUNCT_2:108,A157
                    .= (h").m*((y1-y2).((h+c1).m) - (y1-y2).(c1.m) )
                    by A169,FUNCT_2:108,A157
                    .= (h").m*((y1-y2).(h.m+x0) - (y1-y2).x0 )
                    by A166,A167,A168,SEQ_4:25;
A171:               (y1-y2).(h.m+x0)
                    = y1.(h.m+x0) - y2.(h.m+x0) by A164,A165,VALUED_1:13
                    .= (y1 | [.a,b.]).(h.m+x0) - y2.(h.m+x0)
                    by A165,FUNCT_1:49
                    .= (y1 | [.a,b.]).(h.m+x0) - (y2 | [.a,b.]).(h.m+x0)
                    by A165,FUNCT_1:49
                    .= 0 by A1;
                    (y1-y2).x0 = y1.x0 - y2.x0 by A163,VALUED_1:13
                    .= (y1 | [.a,b.]).x0 - y2.x0 by A143,FUNCT_1:49
                    .= (y1 | [.a,b.]).x0 - (y2 | [.a,b.]).x0
                    by A143,FUNCT_1:49
                    .= 0 by A1;
                    hence thesis by A170,A171;
                  end;
                  hence thesis by A154,COMPLEX1:44;
                end;
                then (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1))
                is convergent by SEQ_2:def 6;
                hence thesis by A153,SEQ_2:def 7;
              end;then
              Rdiff(y1,x0) - Rdiff(y2,x0) = 0 by A147,A148,FDIFF_3:def 6;
              hence thesis;
            end;
            hence thesis by A144,A146,FDIFF_3:22;
          end;
          suppose
A172:       x0 in ].a,b.[;
A173:       ].a,b.[ is open by RCOMP_1:7;
A174:       ].a,b.[ c= [.a,b.]
            proof
              for x0 be object st x0 in ].a,b.[ holds x0 in [.a,b.]
              proof
                let x0 be object such that
A175:           x0 in ].a,b.[;
                x0 in {r where r is Real: a < r & r < b }
                by A175,RCOMP_1:def 2;then
A176:           ex r st r = x0 & a < r & r < b;then
                reconsider x0 as Real;
                x0 in {r where r is Real: a <= r & r <= b } by A176;
                hence thesis by RCOMP_1:def 1;
              end;
              hence thesis;
            end;then
A177:       y1 is_differentiable_on ].a,b.[ by A1,A173,FDIFF_1:26,XBOOLE_1:1;
            then
A178:       y1| (].a,b.[) is_differentiable_on ].a,b.[ &
            (y1| (].a,b.[))`| (].a,b.[) = y1`| (].a,b.[) by FDIFF_2:16;
A179:       (y1`| (].a,b.[)).x0 = diff(y1,x0) by A172,A177,FDIFF_1:def 7;
A180:       y2 is_differentiable_on ].a,b.[
            by A1,A173,A174,FDIFF_1:26,XBOOLE_1:1;
            then
A181:       y2| (].a,b.[) is_differentiable_on ].a,b.[ &
            (y2| (].a,b.[))`| (].a,b.[) = y2`| (].a,b.[) by FDIFF_2:16;
A182:       (y2`| (].a,b.[)).x0 = diff(y2,x0) by A172,A180,FDIFF_1:def 7;
A183:       dom (y1| (].a,b.[) ) = dom y1 /\ (].a,b.[) by RELAT_1:61
            .= ].a,b.[ by A1,A174,XBOOLE_1:1,28
            .= dom y2 /\ (].a,b.[) by A1,A174,XBOOLE_1:1,28
            .= dom (y2| (].a,b.[) ) by RELAT_1:61;
            for x0 be object st x0 in dom (y1| (].a,b.[) ) holds
            (y1| (].a,b.[) ).x0 = (y2| (].a,b.[) ).x0
            proof
              let x0 be object such that
A184:         x0 in dom (y1| (].a,b.[) );
A185:         dom (y1| (].a,b.[) ) = dom y1 /\ (].a,b.[) by RELAT_1:61
              .= ].a,b.[ by A1,A174,XBOOLE_1:1,28;
              then (y1| (].a,b.[) ).x0 = y1.x0 by A184,FUNCT_1:49
              .= (y1| ([.a,b.]) ).x0 by A174,A184,A185,FUNCT_1:49
              .= y2.x0 by A174,A184,A185,A1,FUNCT_1:49
              .= (y2| (].a,b.[) ).x0 by A184,A185,FUNCT_1:49;
              hence thesis;
            end;
            hence thesis by A178,A179,A181,A182,A183,FUNCT_1:2;
          end;
          suppose
A186:       x0 = b;
            then x0 in {r where r is Real: a <= r & r <= b} by A1;then
A187:       x0 in [.a,b.] by RCOMP_1:def 1;then
A188:       y1 is_differentiable_in x0 by A1,FDIFF_1:9;then
A189:       y1 is_left_differentiable_in x0 &
            diff(y1,x0) = Ldiff(y1,x0) by FDIFF_3:22;
            y2 is_differentiable_in x0 by A1,A187,FDIFF_1:9;then
A190:       y2 is_left_differentiable_in x0 &
            diff(y2,x0) = Ldiff(y2,x0) by FDIFF_3:22;
then A191:       y1 - y2 is_left_differentiable_in x0 by A189,FDIFF_3:11;
            Ldiff(y1,x0) = Ldiff(y2,x0)
            proof
A192:         Ldiff(y1,x0) - Ldiff(y2,x0) = Ldiff(y1-y2,x0)
              by A189,A190,FDIFF_3:11;
              for h,c1 st rng c1 = {x0} & rng (h+c1) c= dom (y1-y2) &
              (for n being Nat holds h.n < 0) holds
              lim (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)) = 0
              proof
                let h,c1 such that
A193:           rng c1 = {x0} & rng (h+c1) c= dom (y1-y2) &
                (for n being Nat holds h.n < 0);
A194:           h is convergent & lim h = 0;
A195:           0 < b - a by A6,XREAL_1:50;
                then consider n being Nat such that
A196:           for m being Nat st n<=m holds |.h.m - 0 .| < (x0 - a)/2
                by A186,A194,SEQ_2:def 7;
A197:           for p1 st 0 < p1
                ex n1 being Nat st for m being Nat st n1 <= m holds
                |.(h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m-0 .| < p1
                proof
                  let p1 such that
A198:             0 < p1;
                  take n;
                  for m being Nat st n <= m holds
                  (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m = 0
                  proof
                    let m be Nat such that
A199:               n <= m;
A200:               |.h.m - 0 .| < (x0 - a)/2 by A196,A199;
A201:                 m in NAT by ORDINAL1:def 12;
A202:               h.m < 0 by A193;then
A203:               -h.m < (x0 - a)/2 by A200,ABSVALUE:def 1;
A204:               x0 + h.m <= b + 0 by A186,A202,XREAL_1:7;
                    x0 - (x0 - a)/2 <= x0 - (-h.m) by A203,XREAL_1:13;
                    then
A205:               a + (x0 - a)/2 - (x0 - a)/2 <= x0 + h.m - 0
                    by A186,A195,XREAL_1:13;
A206:               [.a,b.] c= dom y1 /\ dom y2 by A1,XBOOLE_1:19;then
                    x0 in dom y1 /\ dom y2 by A187;then
A207:               x0 in dom(y1-y2) by VALUED_1:12;
A208:               [.a,b.] c= dom(y1-y2) by A206,VALUED_1:12;
                    x0 + h.m in {r where r is Real: a <= r & r <= b }
                    by A204,A205;then
A209:               x0 + h.m in [.a,b.] by RCOMP_1:def 1;
                    x0 in rng c1 by A193,TARSKI:def 1;then
A210:               lim c1 = x0 by SEQ_4:25;
A211:               (h+c1).m = h.m + c1.m by SEQ_1:7
                    .= h.m + x0 by A210,SEQ_4:26;
A212:               rng c1 c= dom (y1-y2)
                    by A193,A207,TARSKI:def 1;
A213:               (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1)).m
                    = (h").m*((y1-y2)/*(h+c1) - (y1-y2)/*c1).m
                    by SEQ_1:8
                    .= (h").m*(((y1-y2)/*(h+c1)).m - ((y1-y2)/*c1).m )
                    by RFUNCT_2:1
                    .= (h").m*((y1-y2).((h+c1).m) - ((y1-y2)/*c1).m )
                    by A193,FUNCT_2:108,A201
                    .= (h").m*((y1-y2).((h+c1).m) - (y1-y2).(c1.m) )
                    by A212,FUNCT_2:108,A201
                    .= (h").m*((y1-y2).(h.m+x0) - (y1-y2).x0 )
                    by A210,A211,SEQ_4:26;
A214:               (y1-y2).(h.m+x0)
                    = y1.(h.m+x0) - y2.(h.m+x0) by A208,A209,VALUED_1:13
                    .= (y1 | [.a,b.]).(h.m+x0) - y2.(h.m+x0)
                    by A209,FUNCT_1:49
                    .= (y1 | [.a,b.]).(h.m+x0) - (y2 | [.a,b.]).(h.m+x0)
                    by A209,FUNCT_1:49
                    .= 0 by A1;
                    (y1-y2).x0 = y1.x0 - y2.x0 by A207,VALUED_1:13
                    .= (y1 | [.a,b.]).x0 - y2.x0 by A187,FUNCT_1:49
                    .= (y1 | [.a,b.]).x0 - (y2 | [.a,b.]).x0
                    by A187,FUNCT_1:49
                    .= 0 by A1;
                    hence thesis by A213,A214;
                  end;
                  hence thesis by A198,COMPLEX1:44;
                end; then
                (h"(#)((y1-y2)/*(h+c1) - (y1-y2)/*c1))
                is convergent by SEQ_2:def 6;
                hence thesis by A197,SEQ_2:def 7;
              end;then
              Ldiff(y1-y2,x0) = 0 by A191,FDIFF_3:def 5;
              hence thesis by A192;
            end;
            hence thesis by A188,A190,FDIFF_3:22;
          end;
        end;
        hence thesis by A131,A132,A133,A134,FUNCT_1:49;
      end;
      hence thesis by A129,A130,FUNCT_1:def 11;
    end;
A215: (u01(#)(x1`|Z) - v01(#)(y1`|Z)) | AB
    = (u02(#)(x2`|Z) - v02(#)(y2`|Z)) | AB
    proof
A216: x1`|Z is PartFunc of REAL,COMPLEX & y1`|Z is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
A217: u01 is PartFunc of REAL,COMPLEX & v01 is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
      u01(#)(x1`|Z) is PartFunc of REAL,COMPLEX &
      v01(#)(y1`|Z) is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;then
A218: (u01(#)(x1`|Z) - v01(#)(y1`|Z)) | AB
      = (u01(#)(x1`|Z)) | AB - (v01(#)(y1`|Z)) | AB by CFUNCT_1:55
      .= (u01| AB)(#)((x1`|Z)| AB) - (v01(#)(y1`|Z)) | AB
      by A216,A217,CFUNCT_1:53
      .= (u01| AB)(#)((x1`|Z)| AB) - (v01| AB)(#)((y1`|Z)| AB)
      by A216,A217,CFUNCT_1:53;
A219: x2`|Z is PartFunc of REAL,COMPLEX & y2`|Z is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
A220: u02 is PartFunc of REAL,COMPLEX & v02 is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
      u02(#)(x2`|Z) is PartFunc of REAL,COMPLEX &
      v02(#)(y2`|Z) is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
      then
      (u02(#)(x2`|Z) - v02(#)(y2`|Z)) | AB
      = (u02(#)(x2`|Z)) | AB - (v02(#)(y2`|Z)) | AB by CFUNCT_1:55
      .= (u02| AB)(#)((x2`|Z)| AB) - (v02(#)(y2`|Z)) | AB
      by A219,A220,CFUNCT_1:53
      .= (u02| AB)(#)((x2`|Z)| AB) - (v02| AB)(#)((y2`|Z)| AB)
      by A219,A220,CFUNCT_1:53;
      hence thesis by A7,A24,A111,A128,A218;
    end;
A221: integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,a,b )
     = integral( (u01(#)(x1`|Z) - v01(#)(y1`|Z)), AB ) by INTEGRA5:19
    .= integral( u02(#)(x2`|Z) - v02(#)(y2`|Z),AB) by A215
    .= integral( u02(#)(x2`|Z) - v02(#)(y2`|Z),a,b ) by INTEGRA5:19;
A222: (v01(#)(x1`|Z) + u01(#)(y1`|Z)) | AB
    = (v02(#)(x2`|Z) + u02(#)(y2`|Z)) | AB
    proof
A223: x1`|Z is PartFunc of REAL,COMPLEX &
      y1`|Z is PartFunc of REAL,COMPLEX by NUMBERS:11,RELSET_1:7;
A224: v01 is PartFunc of REAL,COMPLEX &
      u01 is PartFunc of REAL,COMPLEX by NUMBERS:11,RELSET_1:7;
      v01(#)(x1`|Z) is PartFunc of REAL,COMPLEX &
      u01(#)(y1`|Z) is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7;
      then
A225: (v01(#)(x1`|Z) + u01(#)(y1`|Z)) | AB
      = (v01(#)(x1`|Z)) | AB + (u01(#)(y1`|Z)) | AB by CFUNCT_1:52
      .= (v01| AB)(#)((x1`|Z)| AB) + (u01(#)(y1`|Z)) | AB
      by A223,A224,CFUNCT_1:53
      .= (v01| AB)(#)((x1`|Z)| AB) + (u01| AB)(#)((y1`|Z)| AB)
      by A223,A224,CFUNCT_1:53;
A226: x2`|Z is PartFunc of REAL,COMPLEX &
      y2`|Z is PartFunc of REAL,COMPLEX by NUMBERS:11,RELSET_1:7;
A227: v02 is PartFunc of REAL,COMPLEX &
      u02 is PartFunc of REAL,COMPLEX by NUMBERS:11,RELSET_1:7;
      v02(#)(x2`|Z) is PartFunc of REAL,COMPLEX &
      u02(#)(y2`|Z) is PartFunc of REAL,COMPLEX
      by NUMBERS:11,RELSET_1:7; then
      (v02(#)(x2`|Z) + u02(#)(y2`|Z)) | AB
      = (v02(#)(x2`|Z)) | AB + (u02(#)(y2`|Z)) | AB by CFUNCT_1:52
      .= (v02| AB)(#)((x2`|Z)| AB) + (u02(#)(y2`|Z)) | AB
      by A226,A227,CFUNCT_1:53
      .= (v02| AB)(#)((x2`|Z)| AB) + (u02| AB)(#)((y2`|Z)| AB)
      by A226,A227,CFUNCT_1:53;
      hence thesis by A7,A24,A111,A128,A225;
    end;
    integral( v01(#)(x1`|Z) + u01(#)(y1`|Z),a,b )
    = integral( v01(#)(x1`|Z) + u01(#)(y1`|Z),AB) by INTEGRA5:19
    .= integral( (v02(#)(x2`|Z) + u02(#)(y2`|Z)),AB) by A222
    .= integral( v02(#)(x2`|Z) + u02(#)(y2`|Z),a,b) by INTEGRA5:19;
    hence thesis by A2,A3,A221;
  end;
  suppose
A228: a=b; then
    reconsider BA=[.b,a.] as non empty closed_interval Subset of REAL
    by MEASURE5:14;
A229: integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,a,b )
     = integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,BA) by A228,INTEGRA5:19;
A230: -integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,BA)
    = integral( u01(#)(x1`|Z) - v01(#)(y1`|Z) ,a,b ) by INTEGRA5:20;
A231:integral( v01(#)(x1`|Z) + u01(#)(y1`|Z) ,a,b )
    = integral( v01(#)(x1`|Z) + u01(#)(y1`|Z) ,BA) by A228,INTEGRA5:19;
A232: -integral( v01(#)(x1`|Z) + u01(#)(y1`|Z) ,BA)
    = integral( v01(#)(x1`|Z) + u01(#)(y1`|Z) ,a,b ) by INTEGRA5:20;
 integral( u02(#)(x2`|Z) - v02(#)(y2`|Z) ,a,b )
    = integral( u02(#)(x2`|Z) - v02(#)(y2`|Z) ,BA) by A228,INTEGRA5:19;
then A233: integral( u02(#)(x2`|Z) - v02(#)(y2`|Z) ,a,b )
    = -integral( u02(#)(x2`|Z) - v02(#)(y2`|Z) ,a,b ) by INTEGRA5:20;
    integral( v02(#)(x2`|Z) + u02(#)(y2`|Z) ,a,b )
    = integral( v02(#)(x2`|Z) + u02(#)(y2`|Z) ,AB) by INTEGRA5:19;
    then integral( v02(#)(x2`|Z) + u02(#)(y2`|Z) ,a,b )
    = -integral( v02(#)(x2`|Z) + u02(#)(y2`|Z) ,a,b ) by A228,INTEGRA5:20;
    hence thesis by A2,A3,A229,A230,A231,A232,A233;
  end;
end;

definition
  let f be PartFunc of COMPLEX,COMPLEX;
  let C be C1-curve;
  assume
A1: rng C c= dom f;
  func integral(f,C) -> Complex means :Def4:
  ex a,b be Real,x,y be PartFunc of REAL,REAL, Z be Subset of REAL st
  a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z  is continuous &
  y`|Z is continuous & C = (x+<i>(#)y) | [.a,b.]
  & it = integral(f,x,y,a,b,Z);
  existence
  proof
    consider a,b be Real,x,y be PartFunc of REAL,REAL,
    Z be Subset of REAL such that
A2: a <= b & [.a,b.] = dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
    Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
    y is_differentiable_on Z & x`|Z  is continuous & y`|Z is continuous &
    C = (x+<i>(#)y) | [.a,b.]  by Def3;
     reconsider a,b as Real;
    take integral(f,x,y,a,b,Z);
    thus thesis by A2;
  end;
  uniqueness
  proof
    let s1,s2 be Complex;
    assume
A3: ex a,b be Real,x,y be PartFunc of REAL,REAL,
    Z be Subset of REAL st a <= b & [.a,b.]=dom C &
    [.a,b.] c= dom x & [.a,b.] c= dom y & Z is open &
    [.a,b.] c= Z & x is_differentiable_on Z & y is_differentiable_on Z &
    x`|Z is continuous & y`|Z is continuous & C = (x+<i>(#)y) | [.a,b.] &
    s1 = integral(f,x,y,a,b,Z);
    assume
A4: ex a,b be Real,x,y be PartFunc of REAL,REAL,
    Z be Subset of REAL st a <= b & [.a,b.]=dom C &
    [.a,b.] c= dom x & [.a,b.] c= dom y & Z is open & [.a,b.] c= Z &
    x is_differentiable_on Z & y is_differentiable_on Z &
    x`|Z is continuous & y`|Z is continuous &
    C = (x+<i>(#)y) | [.a,b.] &
    s2 = integral(f,x,y,a,b,Z);
    consider a1,b1 be Real,x1,y1 be PartFunc of REAL,REAL,
    Z1 be Subset of REAL such that
A5: a1 <= b1 & [.a1,b1.]=dom C & [.a1,b1.] c= dom x1 & [.a1,b1.] c= dom y1 &
    Z1 is open & [.a1,b1.] c= Z1 & x1 is_differentiable_on Z1 &
    y1 is_differentiable_on Z1 & x1`|Z1 is continuous &
    y1`|Z1 is continuous & C = (x1+<i>(#)y1) | [.a1,b1.] &
    s1 = integral(f,x1,y1,a1,b1,Z1) by A3;
    consider a2,b2 be Real,x2,y2 be PartFunc of REAL,REAL,
    Z2 be Subset of REAL such that
A6: a2 <= b2 & [.a2,b2.] = dom C & [.a2,b2.] c= dom x2 & [.a2,b2.] c= dom y2 &
    Z2 is open & [.a2,b2.] c= Z2 &
    x2 is_differentiable_on Z2 & y2 is_differentiable_on Z2 &
    x2`|Z2 is continuous & y2`|Z2 is continuous &
    C = (x2+<i>(#)y2) | [.a2,b2.] &
    s2 = integral(f,x2,y2,a2,b2,Z2) by A4;
    dom C is non empty closed_interval Subset of REAL by A5,MEASURE5:14;
    then
A7: a1 = a2 & b1 = b2 by A6,A5,INTEGRA1:5;
    reconsider Z3 = Z1 /\ Z2 as Subset of REAL;
    reconsider ZZ1=Z1, ZZ2= Z2 as Subset of R^1 by TOPMETR:17;
    ZZ1 is open & ZZ2 is open by A5,A6,BORSUK_5:39;then
    ZZ1 /\ ZZ2 is open by TOPS_1:11; then
A8: Z3 is open by BORSUK_5:39;
A9: x1| [.a1,b1.] = x2| [.a2,b2.]
    proof
      for x0 be set st x0 in [.a1,b1.] holds x1.x0 = x2.x0
      proof
        let x0 be set such that
A10:    x0 in [.a1,b1.];
A11:    dom(<i>(#)y1) = dom y1 by VALUED_1:def 5;
        dom(x1+<i>(#)y1) = dom x1 /\ dom(<i>(#)y1) by VALUED_1:def 1;then
A12:    [.a1,b1.] c= dom(x1+<i>(#)y1) by A5,A11,XBOOLE_1:19;
A13:    ((x1+<i>(#)y1) | [.a1,b1.]).x0 = (x1+<i>(#)y1).x0 by A10,FUNCT_1:49
        .= x1.x0 + (<i>(#)y1).x0 by A10,A12,VALUED_1:def 1
        .= x1.x0 + <i>*y1.x0 by VALUED_1:6;
A14:    dom(<i>(#)y2) = dom y2 by VALUED_1:def 5;
    dom(x2+<i>(#)y2) = dom x2 /\ dom(<i>(#)y2) by VALUED_1:def 1;
then A15:    [.a2,b2.] c= dom(x2+<i>(#)y2) by A6,A14,XBOOLE_1:19;
        ((x2+<i>(#)y2) | [.a2,b2.]).x0
        = (x2+<i>(#)y2).x0 by A6,A5,A10,FUNCT_1:49
        .= x2.x0 + (<i>(#)y2).x0 by A6,A5,A10,A15,VALUED_1:def 1
        .= x2.x0 + <i>*y2.x0 by VALUED_1:6;
        hence thesis by A6,A5,A13,COMPLEX1:77;
      end;
      hence thesis by A5,A6,FUNCT_1:95;
    end;
A16: y1| [.a1,b1.] = y2| [.a2,b2.]
    proof
      for x0 be set st x0 in [.a1,b1.] holds y1.x0 = y2.x0
      proof
        let x0 be set such that
A17:    x0 in [.a1,b1.];
A18:    dom(<i>(#)y1) = dom y1 by VALUED_1:def 5;
        dom(x1+<i>(#)y1) = dom x1 /\ dom(<i>(#)y1) by VALUED_1:def 1;then
A19:    [.a1,b1.] c= dom(x1+<i>(#)y1) by A5,A18,XBOOLE_1:19;
A20:    ((x1+<i>(#)y1) | [.a1,b1.]).x0 = (x1+<i>(#)y1).x0 by A17,FUNCT_1:49
        .= x1.x0 + (<i>(#)y1).x0 by A17,A19,VALUED_1:def 1
        .= x1.x0 + <i>*y1.x0 by VALUED_1:6;
A21:    dom(<i>(#)y2) = dom y2 by VALUED_1:def 5;
    dom(x2+<i>(#)y2) = dom x2 /\ dom(<i>(#)y2) by VALUED_1:def 1;
then A22:    [.a2,b2.] c= dom(x2+<i>(#)y2) by A6,A21,XBOOLE_1:19;
        ((x2+<i>(#)y2) | [.a2,b2.]).x0
        = (x2+<i>(#)y2).x0 by A5,A6,A17,FUNCT_1:49
        .= x2.x0 + (<i>(#)y2).x0 by A5,A6,A17,A22,VALUED_1:def 1
        .= x2.x0 + <i>*y2.x0 by VALUED_1:6;
        hence thesis by A6,A5,A20,COMPLEX1:77;
      end;
      hence thesis by A5,A6,FUNCT_1:95;
    end;
A23: [.a1,b1.] c= Z3 by A5,A6,XBOOLE_1:19;
A24: x1 is_differentiable_on Z3 &
    y1 is_differentiable_on Z3 by A5,A8,FDIFF_1:26,XBOOLE_1:17;
A25: x2 is_differentiable_on Z3 &
    y2 is_differentiable_on Z3 by A6,A8,FDIFF_1:26,XBOOLE_1:17;
    thus s1 = integral(f,x1,y1,a1,b1,Z3) by A1,A5,A8,A23,Lm1,XBOOLE_1:17
    .= integral(f,x2,y2,a2,b2,Z3)
    by A1,A5,A6,A7,A8,A9,A16,A24,A25,Lm2,XBOOLE_1:19
    .= s2 by A1,A6,A5,A8,A23,Lm1,XBOOLE_1:17;
  end;
end;

definition
  let f be PartFunc of COMPLEX,COMPLEX;
  let C be C1-curve;
  pred f is_integrable_on C means
  for a,b be Real, x,y be PartFunc of REAL,REAL, Z be Subset of REAL,
  u0,v0 be PartFunc of REAL,REAL st
  (a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous & y`|Z is continuous &
  C = (x+<i>(#)y) | [.a,b.] ) holds
  (u0(#)(x`|Z) - v0(#)(y`|Z)) is_integrable_on [' a,b '] &
  (v0(#)(x`|Z) + u0(#)(y`|Z)) is_integrable_on [' a,b '];
end;

definition
  let f be PartFunc of COMPLEX, COMPLEX;
  let C be C1-curve;
  pred f is_bounded_on C means
  for a,b be Real, x,y be PartFunc of REAL,REAL, Z be Subset of REAL,
  u0, v0 be PartFunc of REAL,REAL st
  (a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous & y`|Z is continuous &
  C = (x+<i>(#)y) | [.a,b.] ) holds
  (u0(#)(x`|Z) - v0(#)(y`|Z))|[' a,b '] is bounded &
  (v0(#)(x`|Z) + u0(#)(y`|Z))|[' a,b '] is bounded;
end;

begin :: Linearity of Complex Intergal

theorem
  for f,g be PartFunc of COMPLEX,COMPLEX, C be C1-curve
  st rng C c= dom f & rng C c= dom g &
  f is_integrable_on C & g is_integrable_on C &
  f is_bounded_on C & g is_bounded_on C
  holds
  integral(f+g,C) = integral(f,C) + integral(g,C)
proof
  let f,g be PartFunc of COMPLEX,COMPLEX,
  C be C1-curve such that
A1: rng C c= dom f & rng C c= dom g & f is_integrable_on C &
  g is_integrable_on C &
  f is_bounded_on C & g is_bounded_on C;
  consider a,b be Real,x,y be PartFunc of REAL,REAL,
  Z be Subset of REAL such that
A2: a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous &
  y`|Z is continuous & C = (x+<i>(#)y) | [.a,b.] by Def3;
  reconsider a,b as Real;
  consider uf0,vf0 be PartFunc of REAL,REAL such that
A3: uf0=(Re f)* (R2-to-C) *<:x,y:> & vf0=(Im f)* (R2-to-C) *<:x,y:> &
  integral(f,x,y,a,b,Z)
  = integral( uf0(#)(x`|Z) - vf0(#)(y`|Z) ,a,b )
  + integral( vf0(#)(x`|Z) + uf0(#)(y`|Z) ,a,b )*<i> by Def2;
  consider ug0,vg0 be PartFunc of REAL,REAL such that
A4: ug0=(Re g)* (R2-to-C) *<:x,y:> & vg0=(Im g)* (R2-to-C) *<:x,y:> &
  integral(g,x,y,a,b,Z)
  = integral( ug0(#)(x`|Z) - vg0(#)(y`|Z) ,a,b )
  + integral( vg0(#)(x`|Z) + ug0(#)(y`|Z) ,a,b )*<i> by Def2;
A5: integral(f,C) = integral(f,x,y,a,b,Z) &
  integral(g,C) = integral(g,x,y,a,b,Z) by A1,A2,Def4;
A6: dom (f+g) = dom f /\ dom g by VALUED_1:def 1;
A7: rng C c= dom f /\ dom g by A1,XBOOLE_1:19;
  consider u0,v0 be PartFunc of REAL,REAL such that
A8: u0=(Re(f+g))* (R2-to-C) *<:x,y:> & v0=(Im(f+g))* (R2-to-C) *<:x,y:> &
  integral(f+g,x,y,a,b,Z)
  = integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i> by Def2;
A9: u0(#)(x`|Z)  = uf0(#)(x`|Z) + ug0(#)(x`|Z)
  proof
A10: dom (uf0(#)(x`|Z) + ug0(#)(x`|Z))
    = dom (uf0(#)(x`|Z)) /\ dom (ug0(#)(x`|Z)) by VALUED_1:def 1
    .= (dom uf0 /\ dom (x`|Z)) /\ dom (ug0(#)(x`|Z)) by VALUED_1:def 4
    .= (dom uf0 /\ dom (x`|Z)) /\ (dom ug0 /\ dom (x`|Z))
    by VALUED_1:def 4
    .= dom uf0 /\ (dom (x`|Z) /\ (dom ug0 /\ dom (x`|Z))) by XBOOLE_1:16
    .= dom uf0 /\ ((dom (x`|Z) /\ dom (x`|Z)) /\ dom ug0) by XBOOLE_1:16
    .= (dom uf0 /\ dom ug0) /\ dom (x`|Z) by XBOOLE_1:16;
A11: dom (u0(#)(x`|Z)) = dom u0 /\ dom (x`|Z) by VALUED_1:def 4;
A12: dom u0 = dom uf0 /\ dom ug0
    proof
A13:  for x0 be object st x0 in dom u0 holds x0 in dom uf0 /\ dom ug0
      proof
        let x0 be object such that
A14:    x0 in dom u0;
A15:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re(f+g))*(R2-to-C)) by A14,A8,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A16:    R2 in dom (R2-to-C) &
        (R2-to-C).R2 in dom (Re(f+g)) by A15,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Re f + Re g) by MESFUN6C:5;then
        (R2-to-C).R2 in (dom Re f /\ dom Re g) by VALUED_1:def 1;
        then
        (R2-to-C).R2 in dom Re f & (R2-to-C).R2 in dom Re g
        by XBOOLE_0:def 4;then
        R2 in dom ((Re f)*(R2-to-C)) &
        R2 in dom ((Re g)*(R2-to-C)) by A16,FUNCT_1:11;then
        x0 in dom uf0 & x0 in dom ug0 by A3,A4,A15,FUNCT_1:11;
        hence thesis by XBOOLE_0:def 4;
      end;
      for x0 be object st x0 in dom uf0 /\ dom ug0 holds x0 in dom u0
      proof
        let x0 be object such that
A17:    x0 in dom uf0 /\ dom ug0;
A18:    x0 in dom uf0 & x0 in dom ug0 by A17,XBOOLE_0:def 4;
then A19:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A20:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re g)*(R2-to-C)) by A18,A4,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A21:    R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re f) by A19,FUNCT_1:11;
        R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re g) by A20,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Re f) /\ dom (Re g) by A21,XBOOLE_0:def 4;
        then
        (R2-to-C).R2 in dom (Re f + Re g) by VALUED_1:def 1;then
        (R2-to-C).R2 in dom (Re (f + g)) by MESFUN6C:5;then
        R2 in dom ((Re (f + g))*(R2-to-C)) by A21,FUNCT_1:11;
        hence thesis by A8,A19,FUNCT_1:11;
      end;
      hence thesis by A13,TARSKI:2;
    end;
    for x0 be object st x0 in dom (u0(#)(x`|Z))
    holds (u0(#)(x`|Z)).x0 = (uf0(#)(x`|Z) + ug0(#)(x`|Z)).x0
    proof
      let x0 be object such that
A22:  x0 in dom (u0(#)(x`|Z));
      x0 in dom u0 /\ dom (x`|Z) by A22,VALUED_1:def 4;then
A23:  x0 in dom u0 & x0 in dom (x`|Z) by XBOOLE_0:def 4;
then A24:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Re (f+g))*(R2-to-C))
      by A8,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A25:  R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re (f+g)) by A24,FUNCT_1:11;
      set c0 = (R2-to-C).R2;
A26:  u0.x0 = ((Re (f+g))*(R2-to-C)).R2 by A8,A23,FUNCT_1:12
      .= (Re (f+g)).c0 by A24,FUNCT_1:12
      .= (Re f + Re g).c0 by MESFUN6C:5;
A27:  c0 in dom (Re f + Re g) by A25,MESFUN6C:5;
A28:  x0 in dom uf0 & x0 in dom ug0 by A12,A23,XBOOLE_0:def 4;
then
A29:  x0 in dom <:x,y:> & R2 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A30:  uf0.x0 = ((Re f)*(R2-to-C)).R2 by A3,A28,FUNCT_1:12
      .= (Re f).c0 by A29,FUNCT_1:12;
A31:  x0 in dom <:x,y:> & R2 in dom ((Re g)*(R2-to-C)) by A4,A28,FUNCT_1:11;
A32:  ug0.x0 = ((Re g)*(R2-to-C)).R2 by A4,A28,FUNCT_1:12
      .= (Re g).c0 by A31,FUNCT_1:12;
      x0 in dom (uf0(#)(x`|Z)) /\ dom (ug0(#)(x`|Z))
      by A10,A11,A12,A22,VALUED_1:def 1;
      then
A33:  x0 in dom (uf0(#)(x`|Z)) & x0 in dom (ug0(#)(x`|Z))
      by XBOOLE_0:def 4;then
A34:  (uf0(#)(x`|Z)).x0 = (Re f).c0*((x`|Z).x0) by A30,VALUED_1:def 4;
A35:  (ug0(#)(x`|Z)).x0 = (Re g).c0*(x`|Z).x0 by A32,A33,VALUED_1:def 4;
      (u0(#)(x`|Z)).x0 = (u0.x0)*((x`|Z).x0) by A22,VALUED_1:def 4
      .= ((Re f).c0 + (Re g).c0)*((x`|Z).x0) by A26,A27,VALUED_1:def 1
      .= (uf0(#)(x`|Z)).x0 + (ug0(#)(x`|Z)).x0 by A35,A34
      .= (uf0(#)(x`|Z) + ug0(#)(x`|Z)).x0 by A10,A11,A12,A22,VALUED_1:def 1;
      hence thesis;
    end;
    hence thesis by A10,A11,A12,FUNCT_1:2;
  end;
A36: v0(#)(x`|Z)  = vf0(#)(x`|Z) + vg0(#)(x`|Z)
  proof
A37: dom (vf0(#)(x`|Z) + vg0(#)(x`|Z))
    = dom (vf0(#)(x`|Z)) /\ dom (vg0(#)(x`|Z)) by VALUED_1:def 1
    .= (dom vf0 /\ dom (x`|Z)) /\ dom (vg0(#)(x`|Z)) by VALUED_1:def 4
    .= (dom vf0 /\ dom (x`|Z)) /\ (dom vg0 /\ dom (x`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ (dom (x`|Z) /\ (dom vg0 /\ dom (x`|Z))) by XBOOLE_1:16
    .= dom vf0 /\ ((dom (x`|Z) /\ dom (x`|Z)) /\ dom vg0) by XBOOLE_1:16
    .= (dom vf0 /\ dom vg0) /\ dom (x`|Z) by XBOOLE_1:16;
A38: dom (v0(#)(x`|Z)) = dom v0 /\ dom (x`|Z) by VALUED_1:def 4;
A39: dom v0 = dom vf0 /\ dom vg0
    proof
A40:  for x0 be object st x0 in dom v0 holds x0 in dom vf0 /\ dom vg0
      proof
        let x0 be object such that
A41:    x0 in dom v0;
A42:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im(f+g))*(R2-to-C)) by A41,A8,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A43:    R2 in dom (R2-to-C) &
        (R2-to-C).R2 in dom (Im(f+g)) by A42,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Im f + Im g) by MESFUN6C:5;then
        (R2-to-C).R2 in (dom Im f /\ dom Im g) by VALUED_1:def 1;
        then
        (R2-to-C).R2 in dom Im f & (R2-to-C).R2 in dom Im g
        by XBOOLE_0:def 4;then
        R2 in dom ((Im f)*(R2-to-C)) &
        R2 in dom ((Im g)*(R2-to-C)) by A43,FUNCT_1:11;then
        x0 in dom vf0 & x0 in dom vg0 by A3,A4,A42,FUNCT_1:11;
        hence thesis by XBOOLE_0:def 4;
      end;
      for x0 be object st x0 in dom vf0 /\ dom vg0 holds x0 in dom v0
      proof
        let x0 be object such that
A44:    x0 in dom vf0 /\ dom vg0;
A45:    x0 in dom vf0 & x0 in dom vg0 by A44,XBOOLE_0:def 4;
then A46:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A47:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im g)*(R2-to-C)) by A45,A4,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A48:    R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im f) by A46,FUNCT_1:11;
        R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im g) by A47,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Im f) /\ dom (Im g) by A48,XBOOLE_0:def 4;
        then
        (R2-to-C).R2 in dom (Im f + Im g) by VALUED_1:def 1;then
        (R2-to-C).R2 in dom (Im (f + g)) by MESFUN6C:5;then
        R2 in dom ((Im (f + g))*(R2-to-C)) by A48,FUNCT_1:11;
        hence thesis by A8,A46,FUNCT_1:11;
      end;
      hence thesis by A40,TARSKI:2;
    end;
    for x0 be object st x0 in dom (v0(#)(x`|Z))
    holds (v0(#)(x`|Z)).x0 = (vf0(#)(x`|Z) + vg0(#)(x`|Z)).x0
    proof
      let x0 be object such that
A49:  x0 in dom (v0(#)(x`|Z));
      x0 in dom v0 /\ dom (x`|Z) by A49,VALUED_1:def 4;then
A50:  x0 in dom v0 & x0 in dom (x`|Z) by XBOOLE_0:def 4;
then A51:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Im (f+g))*(R2-to-C))
      by A8,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A52:  R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im (f+g)) by A51,FUNCT_1:11;
      set c0 = (R2-to-C).R2;
A53:  v0.x0 = ((Im (f+g))*(R2-to-C)).R2 by A8,A50,FUNCT_1:12
      .= (Im (f+g)).c0 by A51,FUNCT_1:12
      .= (Im f + Im g).c0 by MESFUN6C:5;
A54:  c0 in dom (Im f + Im g) by A52,MESFUN6C:5;
A55:  x0 in dom vf0 & x0 in dom vg0 by A39,A50,XBOOLE_0:def 4;
then
A56:  x0 in dom <:x,y:> & R2 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A57:  vf0.x0 = ((Im f)*(R2-to-C)).R2 by A3,A55,FUNCT_1:12
      .= (Im f).c0 by A56,FUNCT_1:12;
A58:  x0 in dom <:x,y:> & R2 in dom ((Im g)*(R2-to-C)) by A4,A55,FUNCT_1:11;
A59:  vg0.x0 = ((Im g)*(R2-to-C)).R2 by A4,A55,FUNCT_1:12
      .= (Im g).c0 by A58,FUNCT_1:12;
      x0 in dom (vf0(#)(x`|Z)) /\ dom (vg0(#)(x`|Z))
      by A37,A38,A39,A49,VALUED_1:def 1;
      then
A60:  x0 in dom (vf0(#)(x`|Z)) & x0 in dom (vg0(#)(x`|Z))
      by XBOOLE_0:def 4;then
A61:  (vf0(#)(x`|Z)).x0 = (Im f).c0*((x`|Z).x0) by A57,VALUED_1:def 4;
A62:  (vg0(#)(x`|Z)).x0 = (Im g).c0*(x`|Z).x0 by A59,A60,VALUED_1:def 4;
      (v0(#)(x`|Z)).x0 = (v0.x0)*((x`|Z).x0) by A49,VALUED_1:def 4
      .= ((Im f).c0 + (Im g).c0)*((x`|Z).x0)
      by A53,A54,VALUED_1:def 1
      .= (vf0(#)(x`|Z)).x0 + (vg0(#)(x`|Z)).x0 by A62,A61
      .= (vf0(#)(x`|Z) + vg0(#)(x`|Z)).x0 by A37,A38,A39,A49,VALUED_1:def 1;
      hence thesis;
    end;
    hence thesis by A37,A38,A39,FUNCT_1:2;
  end;
A63: u0(#)(y`|Z) = uf0(#)(y`|Z) + ug0(#)(y`|Z)
  proof
A64: dom (uf0(#)(y`|Z) + ug0(#)(y`|Z))
    = dom (uf0(#)(y`|Z)) /\ dom (ug0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom uf0 /\ dom (y`|Z)) /\ dom (ug0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom uf0 /\ dom (y`|Z)) /\ (dom ug0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom uf0 /\ (dom (y`|Z) /\ (dom ug0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom uf0 /\ ((dom (y`|Z) /\ dom (y`|Z)) /\ dom ug0) by XBOOLE_1:16
    .= (dom uf0 /\ dom ug0) /\ dom (y`|Z) by XBOOLE_1:16;
A65: dom (u0(#)(y`|Z)) = dom u0 /\ dom (y`|Z) by VALUED_1:def 4;
A66: dom u0 = dom uf0 /\ dom ug0
    proof
A67:  for x0 be object st x0 in dom u0 holds x0 in dom uf0 /\ dom ug0
      proof
        let x0 be object such that
A68:    x0 in dom u0;
A69:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re(f+g))*(R2-to-C)) by A68,A8,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A70:    R2 in dom (R2-to-C) &
        (R2-to-C).R2 in dom (Re(f+g)) by A69,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Re f + Re g) by MESFUN6C:5;then
        (R2-to-C).R2 in (dom Re f /\ dom Re g) by VALUED_1:def 1;
        then
        (R2-to-C).R2 in dom Re f & (R2-to-C).R2 in dom Re g
        by XBOOLE_0:def 4;then
        R2 in dom ((Re f)*(R2-to-C)) &
        R2 in dom ((Re g)*(R2-to-C)) by A70,FUNCT_1:11;then
        x0 in dom uf0 & x0 in dom ug0 by A3,A4,A69,FUNCT_1:11;
        hence thesis by XBOOLE_0:def 4;
      end;
      for x0 be object st x0 in dom uf0 /\ dom ug0 holds x0 in dom u0
      proof
        let x0 be object such that
A71:    x0 in dom uf0 /\ dom ug0;
A72:    x0 in dom uf0 & x0 in dom ug0 by A71,XBOOLE_0:def 4;
then A73:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A74:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Re g)*(R2-to-C)) by A72,A4,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A75:    R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re f) by A73,FUNCT_1:11;
        R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re g) by A74,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Re f) /\ dom (Re g) by A75,XBOOLE_0:def 4;
        then
        (R2-to-C).R2 in dom (Re f + Re g) by VALUED_1:def 1;then
        (R2-to-C).R2 in dom (Re (f + g)) by MESFUN6C:5;then
        R2 in dom ((Re (f + g))*(R2-to-C)) by A75,FUNCT_1:11;
        hence thesis by A8,A73,FUNCT_1:11;
      end;
      hence thesis by A67,TARSKI:2;
    end;
    for x0 be object st x0 in dom (u0(#)(y`|Z))
    holds (u0(#)(y`|Z)).x0 = (uf0(#)(y`|Z) + ug0(#)(y`|Z)).x0
    proof
      let x0 be object such that
A76:  x0 in dom (u0(#)(y`|Z));
      x0 in dom u0 /\ dom (y`|Z) by A76,VALUED_1:def 4;then
A77:  x0 in dom u0 & x0 in dom (y`|Z) by XBOOLE_0:def 4;
then A78:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Re (f+g))*(R2-to-C))
      by A8,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A79:  R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re (f+g)) by A78,FUNCT_1:11;
      set c0 = (R2-to-C).R2;
A80:  u0.x0 = ((Re (f+g))*(R2-to-C)).R2 by A8,A77,FUNCT_1:12
      .= (Re (f+g)).c0 by A78,FUNCT_1:12
      .= (Re f + Re g).c0 by MESFUN6C:5;
A81:  c0 in dom (Re f + Re g) by A79,MESFUN6C:5;
A82:  x0 in dom uf0 & x0 in dom ug0 by A66,A77,XBOOLE_0:def 4;
then
A83:  x0 in dom <:x,y:> & R2 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A84:  uf0.x0 = ((Re f)*(R2-to-C)).R2 by A3,A82,FUNCT_1:12
      .= (Re f).c0 by A83,FUNCT_1:12;
A85:  x0 in dom <:x,y:> & R2 in dom ((Re g)*(R2-to-C)) by A4,A82,FUNCT_1:11;
A86:  ug0.x0 = ((Re g)*(R2-to-C)).R2 by A4,A82,FUNCT_1:12
      .= (Re g).c0 by A85,FUNCT_1:12;
      x0 in dom (uf0(#)(y`|Z)) /\ dom (ug0(#)(y`|Z))
      by A64,A65,A66,A76,VALUED_1:def 1; then
A87:  x0 in dom (uf0(#)(y`|Z)) & x0 in dom (ug0(#)(y`|Z))
      by XBOOLE_0:def 4;then
A88:  (uf0(#)(y`|Z)).x0 = (Re f).c0*((y`|Z).x0) by A84,VALUED_1:def 4;
A89:  (ug0(#)(y`|Z)).x0 = (Re g).c0*(y`|Z).x0 by A86,A87,VALUED_1:def 4;
      (u0(#)(y`|Z)).x0 = (u0.x0)*((y`|Z).x0) by A76,VALUED_1:def 4
      .= ((Re f).c0 + (Re g).c0)*((y`|Z).x0) by A80,A81,VALUED_1:def 1
      .= (uf0(#)(y`|Z)).x0 + (ug0(#)(y`|Z)).x0 by A89,A88
      .= (uf0(#)(y`|Z) + ug0(#)(y`|Z)).x0
      by A64,A65,A66,A76,VALUED_1:def 1;
      hence thesis;
    end;
    hence thesis by A64,A65,A66,FUNCT_1:2;
  end;
A90: v0(#)(y`|Z)  = vf0(#)(y`|Z) + vg0(#)(y`|Z)
  proof
A91: dom (vf0(#)(y`|Z) + vg0(#)(y`|Z))
    = dom (vf0(#)(y`|Z)) /\ dom (vg0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom vf0 /\ dom (y`|Z)) /\ dom (vg0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom vf0 /\ dom (y`|Z)) /\ (dom vg0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ (dom (y`|Z) /\ (dom vg0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom vf0 /\ ((dom (y`|Z) /\ dom (y`|Z)) /\ dom vg0) by XBOOLE_1:16
    .= (dom vf0 /\ dom vg0) /\ dom (y`|Z) by XBOOLE_1:16;
A92: dom (v0(#)(y`|Z)) = dom v0 /\ dom (y`|Z) by VALUED_1:def 4;
A93: dom v0 = dom vf0 /\ dom vg0
    proof
A94:  for x0 be object st x0 in dom v0 holds x0 in dom vf0 /\ dom vg0
      proof
        let x0 be object such that
A95:    x0 in dom v0;
A96:    x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im(f+g))*(R2-to-C)) by A8,A95,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A97:    R2 in dom (R2-to-C) &
        (R2-to-C).R2 in dom (Im(f+g)) by A96,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Im f + Im g) by MESFUN6C:5;then
        (R2-to-C).R2 in (dom Im f /\ dom Im g) by VALUED_1:def 1;
        then
        (R2-to-C).R2 in dom Im f & (R2-to-C).R2 in dom Im g
        by XBOOLE_0:def 4;then
        R2 in dom ((Im f)*(R2-to-C)) &
        R2 in dom ((Im g)*(R2-to-C)) by A97,FUNCT_1:11;then
        x0 in dom vf0 & x0 in dom vg0 by A3,A4,A96,FUNCT_1:11;
        hence thesis by XBOOLE_0:def 4;
      end;
      for x0 be object st x0 in dom vf0 /\ dom vg0 holds x0 in dom v0
      proof
        let x0 be object such that
A98:    x0 in dom vf0 /\ dom vg0;
A99:    x0 in dom vf0 & x0 in dom vg0 by A98,XBOOLE_0:def 4;
then A100:   x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A101:   x0 in dom <:x,y:> &
        <:x,y:>.x0 in dom ((Im g)*(R2-to-C)) by A99,A4,FUNCT_1:11;
        set R2 = <:x,y:>.x0;
A102:   R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im f) by A100,FUNCT_1:11;
        R2 in dom (R2-to-C) &
        (R2-to-C).R2 in dom (Im g) by A101,FUNCT_1:11;then
        (R2-to-C).R2 in dom (Im f) /\ dom (Im g) by A102,XBOOLE_0:def 4;
        then
        (R2-to-C).R2 in dom (Im f + Im g) by VALUED_1:def 1;then
        (R2-to-C).R2 in dom (Im (f + g)) by MESFUN6C:5;then
        R2 in dom ((Im (f + g))*(R2-to-C)) by A102,FUNCT_1:11;
        hence thesis by A8,A100,FUNCT_1:11;
      end;
      hence thesis by A94,TARSKI:2;
    end;
    for x0 be object st x0 in dom (v0(#)(y`|Z))
    holds (v0(#)(y`|Z)).x0 = (vf0(#)(y`|Z) + vg0(#)(y`|Z)).x0
    proof
      let x0 be object such that
A103: x0 in dom (v0(#)(y`|Z));
      x0 in dom v0 /\ dom (y`|Z) by A103,VALUED_1:def 4;then
A104: x0 in dom v0 & x0 in dom (y`|Z) by XBOOLE_0:def 4;
then A105: x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Im (f+g))*(R2-to-C))
      by A8,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A106: R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im (f+g)) by A105,FUNCT_1:11;
      set c0 = (R2-to-C).R2;
A107: v0.x0 = ((Im (f+g))*(R2-to-C)).R2 by A8,A104,FUNCT_1:12
      .= (Im (f+g)).c0 by A105,FUNCT_1:12
      .= (Im f + Im g).c0 by MESFUN6C:5;
A108: c0 in dom (Im f + Im g) by A106,MESFUN6C:5;
A109: x0 in dom vf0 & x0 in dom vg0 by A93,A104,XBOOLE_0:def 4;
then
A110: x0 in dom <:x,y:> & R2 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A111: vf0.x0 = ((Im f)*(R2-to-C)).R2 by A3,A109,FUNCT_1:12
      .= (Im f).c0 by A110,FUNCT_1:12;
A112: x0 in dom <:x,y:> & R2 in dom ((Im g)*(R2-to-C)) by A4,A109,FUNCT_1:11;
A113: vg0.x0 = ((Im g)*(R2-to-C)).R2 by A4,A109,FUNCT_1:12
      .= (Im g).c0 by A112,FUNCT_1:12;
      x0 in dom (vf0(#)(y`|Z)) /\ dom (vg0(#)(y`|Z))
      by A91,A92,A93,A103,VALUED_1:def 1;
      then
A114: x0 in dom (vf0(#)(y`|Z)) & x0 in dom (vg0(#)(y`|Z))
      by XBOOLE_0:def 4;then
A115: (vf0(#)(y`|Z)).x0 = (Im f).c0*((y`|Z).x0) by A111,VALUED_1:def 4;
A116: (vg0(#)(y`|Z)).x0 = (Im g).c0*(y`|Z).x0 by A113,A114,VALUED_1:def 4;
      (v0(#)(y`|Z)).x0 = (v0.x0)*((y`|Z).x0) by A103,VALUED_1:def 4
      .= ((Im f).c0 + (Im g).c0)*((y`|Z).x0) by A107,A108,VALUED_1:def 1
      .= (vf0(#)(y`|Z)).x0 + (vg0(#)(y`|Z)).x0 by A116,A115
      .= (vf0(#)(y`|Z) + vg0(#)(y`|Z)).x0
      by A91,A92,A93,A103,VALUED_1:def 1;
      hence thesis;
    end;
    hence thesis by A91,A92,A93,FUNCT_1:2;
  end;
A117: [.a,b.] c= dom uf0
  proof
      let x0 be object such that
A118: x0 in [.a,b.];
A119: C.x0 in rng C by A2,A118,FUNCT_1:3;
A120: x0 in dom x & x0 in dom y by A2,A118;
A121: x0 in dom x /\ dom y by A118,A2,XBOOLE_0:def 4;then
A122: x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A121,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A123: R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A120,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A118,XBOOLE_0:def 4;
      then
A124: x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A125: [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A126: x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A118,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A124,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A125,A126,Def1
      .= (R2-to-C).R2 by A121,FUNCT_3:48;then
      (R2-to-C).R2 in dom f by A1,A119;then
      (R2-to-C).R2 in dom (Re f) by COMSEQ_3:def 3;then
      R2 in dom ((Re f)* (R2-to-C)) by A123,FUNCT_1:11;
      hence thesis by A3,A122,FUNCT_1:11;
  end;
A127: [.a,b.] c= dom vf0
  proof
      let x0 be object such that
A128: x0 in [.a,b.];
A129: C.x0 in rng C by A2,A128,FUNCT_1:3;
A130: x0 in dom x & x0 in dom y by A2,A128;
A131: x0 in dom x /\ dom y by A2,A128,XBOOLE_0:def 4;then
A132: x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A131,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A133: R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A130,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A128,XBOOLE_0:def 4;
      then
A134: x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A135: [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A136: x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A128,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A134,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A135,A136,Def1
      .= (R2-to-C).R2 by A131,FUNCT_3:48;then
      (R2-to-C).R2 in dom f by A1,A129;then
      (R2-to-C).R2 in dom (Im f) by COMSEQ_3:def 4;then
      R2 in dom ((Im f)* (R2-to-C)) by A133,FUNCT_1:11;
      hence thesis by A3,A132,FUNCT_1:11;
  end;
A137: [.a,b.] c= dom ug0
  proof
      let x0 be object such that
A138: x0 in [.a,b.];
A139: C.x0 in rng C by A138,A2,FUNCT_1:3;
A140: x0 in dom x & x0 in dom y by A2,A138;
A141: x0 in dom x /\ dom y by A2,A138,XBOOLE_0:def 4;then
A142: x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A141,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A143: R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A140,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A138,XBOOLE_0:def 4;
      then
A144: x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A145: [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A146: x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A138,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A144,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A145,A146,Def1
      .= (R2-to-C).R2 by A141,FUNCT_3:48;then
      (R2-to-C).R2 in dom g by A1,A139;then
      (R2-to-C).R2 in dom (Re g) by COMSEQ_3:def 3;then
      R2 in dom ((Re g)* (R2-to-C)) by A143,FUNCT_1:11;
      hence thesis by A4,A142,FUNCT_1:11;
  end;
A147: [.a,b.] c= dom vg0
  proof
      let x0 be object such that
A148: x0 in [.a,b.];
A149: C.x0 in rng C by A2,A148,FUNCT_1:3;
A150: x0 in dom x & x0 in dom y by A2,A148;
A151: x0 in dom x /\ dom y by A148,A2,XBOOLE_0:def 4;then
A152: x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A151,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A153: R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A150,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A148,XBOOLE_0:def 4;
      then
A154: x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A155: [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A156: x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A148,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A154,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A155,A156,Def1
      .= (R2-to-C).R2 by A151,FUNCT_3:48;then
      (R2-to-C).R2 in dom g by A1,A149;then
      (R2-to-C).R2 in dom (Im g) by COMSEQ_3:def 4;then
      R2 in dom ((Im g)* (R2-to-C)) by A153,FUNCT_1:11;
      hence thesis by A4,A152,FUNCT_1:11;
  end;
A157: [' a,b '] c= dom (uf0(#)(x`|Z) - vf0(#)(y`|Z))
  proof
A158: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A159: dom (uf0(#)(x`|Z) - vf0(#)(y`|Z))
    = dom (uf0(#)(x`|Z)) /\ dom (vf0(#)(y`|Z)) by VALUED_1:12
    .= (dom uf0 /\ dom (x`|Z)) /\ dom (vf0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom uf0 /\ dom (x`|Z)) /\ (dom vf0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom uf0 /\ ((dom (x`|Z)) /\ (dom vf0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom uf0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom vf0)) by A2,FDIFF_1:def 7
    .= dom uf0 /\ (Z /\ (Z /\ dom vf0)) by A2,FDIFF_1:def 7
    .= dom uf0 /\ ((Z /\ Z) /\ dom vf0) by XBOOLE_1:16
    .= (dom uf0 /\ dom vf0) /\ Z by XBOOLE_1:16;
    [.a,b.] c= dom uf0 /\ dom vf0 by A117,A127,XBOOLE_1:19;
    hence thesis by A2,A158,A159,XBOOLE_1:19;
  end;
A160: [' a,b '] c= dom (ug0(#)(x`|Z) - vg0(#)(y`|Z))
  proof
A161: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A162: dom (ug0(#)(x`|Z) - vg0(#)(y`|Z))
    = dom (ug0(#)(x`|Z)) /\ dom (vg0(#)(y`|Z)) by VALUED_1:12
    .= (dom ug0 /\ dom (x`|Z)) /\ dom (vg0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom ug0 /\ dom (x`|Z)) /\ (dom vg0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom ug0 /\ ((dom (x`|Z)) /\ (dom vg0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom ug0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom vg0)) by A2,FDIFF_1:def 7
    .= dom ug0 /\ (Z /\ (Z /\ dom vg0)) by A2,FDIFF_1:def 7
    .= dom ug0 /\ ((Z /\ Z) /\ dom vg0) by XBOOLE_1:16
    .= (dom ug0 /\ dom vg0) /\ Z by XBOOLE_1:16;
    [.a,b.] c= dom ug0 /\ dom vg0 by A137,A147,XBOOLE_1:19;
    hence thesis by A2,A161,A162,XBOOLE_1:19;
  end;
A163: [' a,b '] c= dom (vf0(#)(x`|Z) + uf0(#)(y`|Z))
  proof
A164: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A165: dom (vf0(#)(x`|Z) + uf0(#)(y`|Z))
    = dom (vf0(#)(x`|Z)) /\ dom (uf0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom vf0 /\ dom (x`|Z)) /\ dom (uf0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom vf0 /\ dom (x`|Z)) /\ (dom uf0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ ((dom (x`|Z)) /\ (dom uf0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom vf0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom uf0)) by A2,FDIFF_1:def 7
    .= dom vf0 /\ (Z /\ (Z /\ dom uf0)) by A2,FDIFF_1:def 7
    .= dom vf0 /\ ((Z /\ Z) /\ dom uf0) by XBOOLE_1:16
    .= (dom vf0 /\ dom uf0) /\ Z by XBOOLE_1:16;
    [.a,b.] c= dom vf0 /\ dom uf0 by A117,A127,XBOOLE_1:19;
    hence thesis by A2,A164,A165,XBOOLE_1:19;
  end;
A166: [' a,b '] c= dom (vg0(#)(x`|Z) + ug0(#)(y`|Z))
  proof
A167: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A168: dom (vg0(#)(x`|Z) + ug0(#)(y`|Z))
    = dom (vg0(#)(x`|Z)) /\ dom (ug0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom vg0 /\ dom (x`|Z)) /\ dom (ug0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom vg0 /\ dom (x`|Z)) /\ (dom ug0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom vg0 /\ ((dom (x`|Z)) /\ (dom ug0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom vg0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom ug0)) by A2,FDIFF_1:def 7
    .= dom vg0 /\ (Z /\ (Z /\ dom ug0)) by A2,FDIFF_1:def 7
    .= dom vg0 /\ ((Z /\ Z) /\ dom ug0) by XBOOLE_1:16
    .= (dom vg0 /\ dom ug0) /\ Z by XBOOLE_1:16;
    [.a,b.] c= dom ug0 /\ dom vg0 by A137,A147,XBOOLE_1:19;
    hence thesis by A2,A167,A168,XBOOLE_1:19;
  end;
  reconsider a,b as Real;
A169: (uf0(#)(x`|Z) - vf0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A170: (ug0(#)(x`|Z) - vg0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A171: (vf0(#)(x`|Z) + uf0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A172: (vg0(#)(x`|Z) + ug0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A173: (uf0(#)(x`|Z) - vf0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
A174: (ug0(#)(x`|Z) - vg0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
A175: (vf0(#)(x`|Z) + uf0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
A176: (vg0(#)(x`|Z) + ug0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
  integral(f+g,C)
  = integral(uf0(#)(x`|Z)+ug0(#)(x`|Z)-(vf0(#)(y`|Z)+vg0(#)(y`|Z)),a,b )
  + integral(vf0(#)(x`|Z)+vg0(#)(x`|Z)+(uf0(#)(y`|Z)+ug0(#)(y`|Z)),a,b )*<i>
  by A36,A63,A9,A90,A8,A2,A6,A7,Def4
  .= integral(uf0(#)(x`|Z)+ug0(#)(x`|Z)-vf0(#)(y`|Z)-vg0(#)(y`|Z),a,b )
  + integral(vf0(#)(x`|Z)+vg0(#)(x`|Z)+(uf0(#)(y`|Z)+ug0(#)(y`|Z)),a,b )*<i>
  by RFUNCT_1:20
  .= integral(uf0(#)(x`|Z)+ug0(#)(x`|Z)-vf0(#)(y`|Z)-vg0(#)(y`|Z),a,b )
  + integral(vf0(#)(x`|Z)+vg0(#)(x`|Z)+uf0(#)(y`|Z)+ug0(#)(y`|Z),a,b )*<i>
  by RFUNCT_1:8
  .= integral(uf0(#)(x`|Z)-vf0(#)(y`|Z)+ug0(#)(x`|Z)-vg0(#)(y`|Z),a,b )
  + integral(vf0(#)(x`|Z)+vg0(#)(x`|Z)+uf0(#)(y`|Z)+ug0(#)(y`|Z),a,b )*<i>
  by RFUNCT_1:8
  .= integral(uf0(#)(x`|Z)-vf0(#)(y`|Z) + ug0(#)(x`|Z)-vg0(#)(y`|Z),a,b )
  + integral(vf0(#)(x`|Z)+uf0(#)(y`|Z) + vg0(#)(x`|Z)+ug0(#)(y`|Z),a,b )*<i>
  by RFUNCT_1:8
  .= integral((uf0(#)(x`|Z)-vf0(#)(y`|Z)) + (ug0(#)(x`|Z)-vg0(#)(y`|Z)),a,b )
  + integral(vf0(#)(x`|Z)+uf0(#)(y`|Z) + vg0(#)(x`|Z)+ug0(#)(y`|Z),a,b )*<i>
  by RFUNCT_1:8
  .= integral((uf0(#)(x`|Z)-vf0(#)(y`|Z))
  + (ug0(#)(x`|Z)-vg0(#)(y`|Z)),a,b )
  + integral((vf0(#)(x`|Z)+uf0(#)(y`|Z))
  + (vg0(#)(x`|Z)+ug0(#)(y`|Z)),a,b )*<i> by RFUNCT_1:8
  .= integral(uf0(#)(x`|Z)-vf0(#)(y`|Z),a,b )
  + integral(ug0(#)(x`|Z)-vg0(#)(y`|Z),a,b )
  + integral((vf0(#)(x`|Z)+uf0(#)(y`|Z))
  + (vg0(#)(x`|Z)+ug0(#)(y`|Z)),a,b )*<i>
  by A2,A157,A160,A169,A170,A173,A174,INTEGRA6:12
  .= integral(uf0(#)(x`|Z)-vf0(#)(y`|Z),a,b )
  + integral(ug0(#)(x`|Z)-vg0(#)(y`|Z),a,b )
  + (integral(vf0(#)(x`|Z)+uf0(#)(y`|Z),a,b )
  + integral(vg0(#)(x`|Z)+ug0(#)(y`|Z),a,b ))*<i>
  by A2,A163,A166,A171,A172,A175,A176,INTEGRA6:12
  .= integral(f,C) + integral(g,C) by A4,A5,A3;
  hence thesis;
end;

theorem
  for f be PartFunc of COMPLEX,COMPLEX,
  C be C1-curve st rng C c= dom f & f is_integrable_on C &
  f is_bounded_on C holds
  for r be Real holds
  integral(r(#)f,C) = r*integral(f,C)
proof
  let f be PartFunc of COMPLEX,COMPLEX,
  C be C1-curve such that
A1: rng C c= dom f & f is_integrable_on C & f is_bounded_on C;
  let r be Real;
  consider a,b be Real,x,y be PartFunc of REAL,REAL,
  Z be Subset of REAL such that
A2: a <= b & [.a,b.]=dom C & [.a,b.] c= dom x & [.a,b.] c= dom y &
  Z is open & [.a,b.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous & y`|Z is continuous &
  C = (x+<i>(#)y) | [.a,b.] by Def3;
  reconsider a,b as Real;
  consider uf0,vf0 be PartFunc of REAL,REAL such that
A3: uf0=(Re f)* (R2-to-C) *<:x,y:> & vf0=(Im f)* (R2-to-C) *<:x,y:> &
  integral(f,x,y,a,b,Z)
  = integral( uf0(#)(x`|Z) - vf0(#)(y`|Z) ,a,b )
  + integral( vf0(#)(x`|Z) + uf0(#)(y`|Z) ,a,b )*<i> by Def2;
A4: dom (r(#)f) = dom f by VALUED_1:def 5;
  consider u0,v0 be PartFunc of REAL,REAL such that
A5: u0=(Re(r(#)f))* (R2-to-C) *<:x,y:> & v0=(Im(r(#)f))* (R2-to-C) *<:x,y:> &
  integral(r(#)f,x,y,a,b,Z) = integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i> by Def2;
A6: dom u0 = dom uf0
  proof
A7: for x0 be object st x0 in dom u0 holds x0 in dom uf0
    proof
      let x0 be object such that
A8:   x0 in dom u0;
A9:   x0 in dom <:x,y:> &
      <:x,y:>.x0 in dom ((Re(r(#)f))*(R2-to-C)) by A5,A8,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A10:  R2 in dom (R2-to-C) &
      (R2-to-C).R2 in dom (Re(r(#)f)) by A9,FUNCT_1:11;then
      (R2-to-C).R2 in dom (r(#)Re f) by MESFUN6C:2;then
      (R2-to-C).R2 in (dom Re f) by VALUED_1:def 5;then
      R2 in dom ((Re f)*(R2-to-C)) by A10,FUNCT_1:11;
      hence thesis by A3,A9,FUNCT_1:11;
    end;
    for x0 be object st x0 in dom uf0 holds x0 in dom u0
    proof
      let x0 be object such that
A11:  x0 in dom uf0;
A12:  x0 in dom <:x,y:> &
      <:x,y:>.x0 in dom ((Re f)*(R2-to-C)) by A3,A11,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A13:  R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Re f) by A12,FUNCT_1:11;then
      (R2-to-C).R2 in dom (r(#)Re f) by VALUED_1:def 5;then
      (R2-to-C).R2 in dom (Re(r(#)f)) by MESFUN6C:2;then
      R2 in dom ((Re (r(#)f))*(R2-to-C)) by A13,FUNCT_1:11;
      hence thesis by A5,A12,FUNCT_1:11;
    end;
    hence thesis by A7,TARSKI:2;
  end;
A14: dom v0 = dom vf0
  proof
A15: for x0 be object st x0 in dom v0 holds x0 in dom vf0
    proof
      let x0 be object such that
A16:  x0 in dom v0;
A17:  x0 in dom <:x,y:> &
      <:x,y:>.x0 in dom ((Im(r(#)f))*(R2-to-C)) by A16,A5,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A18:  R2 in dom (R2-to-C) &
      (R2-to-C).R2 in dom (Im(r(#)f)) by A17,FUNCT_1:11;then
      (R2-to-C).R2 in dom (r(#)Im f) by MESFUN6C:2;then
      (R2-to-C).R2 in (dom Im f) by VALUED_1:def 5;then
      R2 in dom ((Im f)*(R2-to-C)) by A18,FUNCT_1:11;
      hence thesis by A3,A17,FUNCT_1:11;
    end;
    for x0 be object st x0 in dom vf0 holds x0 in dom v0
    proof
      let x0 be object such that
A19:  x0 in dom vf0;
A20:  x0 in dom <:x,y:> &
      <:x,y:>.x0 in dom ((Im f)*(R2-to-C)) by A19,A3,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
A21:  R2 in dom (R2-to-C) & (R2-to-C).R2 in dom (Im f) by A20,FUNCT_1:11;then
      (R2-to-C).R2 in dom (r(#)Im f) by VALUED_1:def 5;then
      (R2-to-C).R2 in dom (Im(r(#)f)) by MESFUN6C:2;then
      R2 in dom ((Im (r(#)f))*(R2-to-C)) by A21,FUNCT_1:11;
      hence thesis by A5,A20,FUNCT_1:11;
    end;
    hence thesis by A15,TARSKI:2;
  end;
A22: u0(#)(x`|Z) = r(#)(uf0(#)(x`|Z))
  proof
A23: dom (r(#)(uf0(#)(x`|Z))) = dom (uf0(#)(r(#)(x`|Z))) by RFUNCT_1:13
    .= dom(uf0) /\ dom (r(#)(x`|Z)) by VALUED_1:def 4
    .= dom uf0 /\ dom (x`|Z) by VALUED_1:def 5;
A24: dom (u0(#)(x`|Z)) = dom u0 /\ dom (x`|Z) by VALUED_1:def 4;
A25: dom (u0(#)(x`|Z)) = dom (r(#)(uf0(#)(x`|Z))) by A6,A23,VALUED_1:def 4;
    for x0 be object st x0 in dom (u0(#)(x`|Z))
    holds (u0(#)(x`|Z)).x0 = (r(#)(uf0(#)(x`|Z))).x0
    proof
      let x0 be object such that
A26:  x0 in dom (u0(#)(x`|Z));
A27:  x0 in dom u0 /\ dom (x`|Z) by A26,VALUED_1:def 4;then
A28:  x0 in dom u0 & x0 in dom (x`|Z) by XBOOLE_0:def 4;
then A29:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Re (r(#)f))*(R2-to-C))
      by A5,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
      set c0 = (R2-to-C).R2;
A30:  u0.x0 = ((Re (r(#)f))*(R2-to-C)).R2 by A5,A28,FUNCT_1:12
      .= (Re (r(#)f)).c0 by A29,FUNCT_1:12
      .= (r(#)Re f).c0 by MESFUN6C:2;
  x0 in dom uf0 by A6,A27,XBOOLE_0:def 4;
then
A31:  x0 in dom <:x,y:> & R2 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A32:  uf0.x0 = ((Re f)*(R2-to-C)).R2 by A3,A6,A28,FUNCT_1:12
      .= (Re f).c0 by A31,FUNCT_1:12;
A33:  x0 in dom (uf0(#)(r(#)(x`|Z))) by A26,A25,RFUNCT_1:13;then
      x0 in dom (uf0) /\ dom (r(#)(x`|Z)) by VALUED_1:def 4;
      then
A34:  x0 in dom (r(#)(x`|Z)) by XBOOLE_0:def 4;
      (u0(#)(x`|Z)).x0 = (u0.x0)*((x`|Z).x0) by A26,VALUED_1:def 4
      .= (r*(Re f).c0)*((x`|Z).x0) by A30,VALUED_1:6
      .= uf0.x0*(r*((x`|Z).x0)) by A32
      .= uf0.x0*(r(#)(x`|Z)).x0 by A34,VALUED_1:def 5
      .= (uf0(#)(r(#)(x`|Z))).x0 by A33,VALUED_1:def 4
      .= (r(#)(uf0(#)(x`|Z))).x0 by RFUNCT_1:13;
      hence thesis;
    end;
    hence thesis by A6,A23,A24,FUNCT_1:2;
  end;
A35: v0(#)(x`|Z)  = r(#)(vf0(#)(x`|Z))
  proof
A36: dom (r(#)(vf0(#)(x`|Z))) = dom (vf0(#)(r(#)(x`|Z))) by RFUNCT_1:13
    .= dom(vf0) /\ dom (r(#)(x`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ dom (x`|Z) by VALUED_1:def 5;
A37: dom (v0(#)(x`|Z)) = dom v0 /\ dom (x`|Z) by VALUED_1:def 4;
A38: dom (v0(#)(x`|Z)) = dom (r(#)(vf0(#)(x`|Z))) by A14,A36,VALUED_1:def 4;
    for x0 be object st x0 in dom (v0(#)(x`|Z))
    holds (v0(#)(x`|Z)).x0 = (r(#)(vf0(#)(x`|Z))).x0
    proof
      let x0 be object such that
A39:  x0 in dom (v0(#)(x`|Z));
A40:  x0 in dom v0 /\ dom (x`|Z) by A39,VALUED_1:def 4;then
A41:  x0 in dom v0 & x0 in dom (x`|Z) by XBOOLE_0:def 4;
then A42:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Im (r(#)f))*(R2-to-C))
      by A5,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
      set c0 = (R2-to-C).R2;
A43:  v0.x0 = ((Im (r(#)f))*(R2-to-C)).R2 by A5,A41,FUNCT_1:12
      .= (Im (r(#)f)).c0 by A42,FUNCT_1:12
      .= (r(#)Im f).c0 by MESFUN6C:2;
  x0 in dom vf0 by A14,A40,XBOOLE_0:def 4;
then
A44:  x0 in dom <:x,y:> & R2 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A45:  vf0.x0 = ((Im f)*(R2-to-C)).R2 by A3,A14,A41,FUNCT_1:12
      .= (Im f).c0 by A44,FUNCT_1:12;
A46:  x0 in dom (vf0(#)(r(#)(x`|Z))) by A38,A39,RFUNCT_1:13;then
      x0 in dom (vf0) /\ dom (r(#)(x`|Z)) by VALUED_1:def 4; then
A47:  x0 in dom (r(#)(x`|Z)) by XBOOLE_0:def 4;
      (v0(#)(x`|Z)).x0 = (v0.x0)*((x`|Z).x0) by A39,VALUED_1:def 4
      .= (r*(Im f).c0)*((x`|Z).x0) by A43,VALUED_1:6
      .= vf0.x0*(r*((x`|Z).x0)) by A45
      .= vf0.x0*(r(#)(x`|Z)).x0 by A47,VALUED_1:def 5
      .= (vf0(#)(r(#)(x`|Z))).x0 by A46,VALUED_1:def 4
      .= (r(#)(vf0(#)(x`|Z))).x0 by RFUNCT_1:13;
      hence thesis;
    end;
    hence thesis by A14,A36,A37,FUNCT_1:2;
  end;
A48: u0(#)(y`|Z) = r(#)(uf0(#)(y`|Z))
  proof
A49: dom (r(#)(uf0(#)(y`|Z))) = dom (uf0(#)(r(#)(y`|Z))) by RFUNCT_1:13
    .= dom(uf0) /\ dom (r(#)(y`|Z)) by VALUED_1:def 4
    .= dom uf0 /\ dom (y`|Z) by VALUED_1:def 5;
A50: dom (u0(#)(y`|Z)) = dom u0 /\ dom (y`|Z) by VALUED_1:def 4;
A51: dom (u0(#)(y`|Z)) = dom (r(#)(uf0(#)(y`|Z))) by A6,A49,VALUED_1:def 4;
    for x0 be object st x0 in dom (u0(#)(y`|Z))
    holds (u0(#)(y`|Z)).x0 = (r(#)(uf0(#)(y`|Z))).x0
    proof
      let x0 be object such that
A52:  x0 in dom (u0(#)(y`|Z));
A53:  x0 in dom u0 /\ dom (y`|Z) by A52,VALUED_1:def 4;then
A54:  x0 in dom u0 & x0 in dom (y`|Z) by XBOOLE_0:def 4;
then A55:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Re (r(#)f))*(R2-to-C))
      by A5,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
      set c0 = (R2-to-C).R2;
A56:  u0.x0 = ((Re (r(#)f))*(R2-to-C)).R2 by A5,A54,FUNCT_1:12
      .= (Re (r(#)f)).c0 by A55,FUNCT_1:12
      .= (r(#)Re f).c0 by MESFUN6C:2;
  x0 in dom uf0 by A6,A53,XBOOLE_0:def 4;
then
A57:  x0 in dom <:x,y:> & R2 in dom ((Re f)*(R2-to-C)) by A3,FUNCT_1:11;
A58:  uf0.x0 = ((Re f)*(R2-to-C)).R2 by A3,A6,A54,FUNCT_1:12
      .= (Re f).c0 by A57,FUNCT_1:12;
A59:  x0 in dom (uf0(#)(r(#)(y`|Z))) by A51,A52,RFUNCT_1:13;then
      x0 in dom (uf0) /\ dom (r(#)(y`|Z)) by VALUED_1:def 4;
      then
A60:  x0 in dom (r(#)(y`|Z)) by XBOOLE_0:def 4;
      (u0(#)(y`|Z)).x0 = (u0.x0)*((y`|Z).x0) by A52,VALUED_1:def 4
      .= (r*(Re f).c0)*((y`|Z).x0) by A56,VALUED_1:6
      .= uf0.x0*(r*((y`|Z).x0)) by A58
      .= uf0.x0*(r(#)(y`|Z)).x0 by A60,VALUED_1:def 5
      .= (uf0(#)(r(#)(y`|Z))).x0 by A59,VALUED_1:def 4
      .= (r(#)(uf0(#)(y`|Z))).x0 by RFUNCT_1:13;
      hence thesis;
    end;
    hence thesis by A6,A49,A50,FUNCT_1:2;
  end;
A61: v0(#)(y`|Z)  = r(#)(vf0(#)(y`|Z))
  proof
A62: dom (r(#)(vf0(#)(y`|Z))) = dom (vf0(#)(r(#)(y`|Z))) by RFUNCT_1:13
    .= dom(vf0) /\ dom (r(#)(y`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ dom (y`|Z) by VALUED_1:def 5;
A63: dom (v0(#)(y`|Z)) = dom v0 /\ dom (y`|Z) by VALUED_1:def 4;
A64: dom (v0(#)(y`|Z)) = dom (r(#)(vf0(#)(y`|Z))) by A14,A62,VALUED_1:def 4;
    for x0 be object st x0 in dom (v0(#)(y`|Z))
    holds (v0(#)(y`|Z)).x0 = (r(#)(vf0(#)(y`|Z))).x0
    proof
      let x0 be object such that
A65:  x0 in dom (v0(#)(y`|Z));
A66:  x0 in dom v0 /\ dom (y`|Z) by A65,VALUED_1:def 4;then
A67:  x0 in dom v0 & x0 in dom (y`|Z) by XBOOLE_0:def 4;
then A68:  x0 in dom <:x,y:> & <:x,y:>.x0 in dom ((Im (r(#)f))*(R2-to-C))
      by A5,FUNCT_1:11;
      set R2 = <:x,y:>.x0;
      set c0 = (R2-to-C).R2;
A69:  v0.x0 = ((Im (r(#)f))*(R2-to-C)).R2 by A5,A67,FUNCT_1:12
      .= (Im (r(#)f)).c0 by A68,FUNCT_1:12
      .= (r(#)Im f).c0 by MESFUN6C:2;
  x0 in dom vf0 by A14,A66,XBOOLE_0:def 4;
then
A70:  x0 in dom <:x,y:> & R2 in dom ((Im f)*(R2-to-C)) by A3,FUNCT_1:11;
A71:  vf0.x0 = ((Im f)*(R2-to-C)).R2 by A3,A14,A67,FUNCT_1:12
      .= (Im f).c0 by A70,FUNCT_1:12;
A72:  x0 in dom (vf0(#)(r(#)(y`|Z))) by A64,A65,RFUNCT_1:13;then
      x0 in dom (vf0) /\ dom (r(#)(y`|Z)) by VALUED_1:def 4;
      then
A73:  x0 in dom (r(#)(y`|Z)) by XBOOLE_0:def 4;
      (v0(#)(y`|Z)).x0 = (v0.x0)*((y`|Z).x0) by A65,VALUED_1:def 4
      .= (r*(Im f).c0)*((y`|Z).x0) by A69,VALUED_1:6
      .= vf0.x0*(r*((y`|Z).x0)) by A71
      .= vf0.x0*(r(#)(y`|Z)).x0 by A73,VALUED_1:def 5
      .= (vf0(#)(r(#)(y`|Z))).x0 by A72,VALUED_1:def 4
      .= (r(#)(vf0(#)(y`|Z))).x0 by RFUNCT_1:13;
      hence thesis;
    end;
    hence thesis by A14,A62,A63,FUNCT_1:2;
  end;
A74: [.a,b.] c= dom uf0
  proof
      let x0 be object such that
A75:  x0 in [.a,b.];
A76:  C.x0 in rng C by A2,A75,FUNCT_1:3;
A77:  x0 in dom x & x0 in dom y by A2,A75;
A78:  x0 in dom x /\ dom y by A2,A75,XBOOLE_0:def 4;then
A79:  x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A78,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A80:  R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A77,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A75,XBOOLE_0:def 4;
      then
A81:  x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A82:  [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A83:  x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A75,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A81,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A82,A83,Def1
      .= (R2-to-C).R2 by A78,FUNCT_3:48;then
      (R2-to-C).R2 in dom f by A1,A76;then
      (R2-to-C).R2 in dom (Re f) by COMSEQ_3:def 3;then
      R2 in dom ((Re f)* (R2-to-C)) by A80,FUNCT_1:11;
      hence thesis by A3,A79,FUNCT_1:11;
  end;
A84: [.a,b.] c= dom vf0
  proof
      let x0 be object such that
A85:  x0 in [.a,b.];
A86:  C.x0 in rng C by A2,A85,FUNCT_1:3;
A87:  x0 in dom x & x0 in dom y by A2,A85;
A88:  x0 in dom x /\ dom y by A2,A85,XBOOLE_0:def 4;then
A89:  x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A88,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A90:  R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A87,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A2,A85,XBOOLE_0:def 4; then
A91:  x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A92:  [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A93:  x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A85,A2,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A91,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A92,A93,Def1
      .= (R2-to-C).R2 by A88,FUNCT_3:48; then
      (R2-to-C).R2 in dom f by A1,A86;then
      (R2-to-C).R2 in dom (Im f) by COMSEQ_3:def 4;then
      R2 in dom ((Im f)* (R2-to-C)) by A90,FUNCT_1:11;
      hence thesis by A3,A89,FUNCT_1:11;
  end;
A94: [' a,b '] c= dom (uf0(#)(x`|Z) - vf0(#)(y`|Z))
  proof
A95: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A96: dom (uf0(#)(x`|Z) - vf0(#)(y`|Z))
    = dom (uf0(#)(x`|Z)) /\ dom (vf0(#)(y`|Z)) by VALUED_1:12
    .= (dom uf0 /\ dom (x`|Z)) /\ dom (vf0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom uf0 /\ dom (x`|Z)) /\ (dom vf0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom uf0 /\ ((dom (x`|Z)) /\ (dom vf0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom uf0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom vf0)) by A2,FDIFF_1:def 7
    .= dom uf0 /\ (Z /\ (Z /\ dom vf0)) by A2,FDIFF_1:def 7
    .= dom uf0 /\ ((Z /\ Z) /\ dom vf0)  by XBOOLE_1:16
    .= (dom uf0 /\ dom vf0) /\ Z  by XBOOLE_1:16;
    [.a,b.] c= dom uf0 /\ dom vf0 by A74,A84,XBOOLE_1:19;
    hence thesis by A2,A95,A96,XBOOLE_1:19;
  end;
A97: [' a,b '] c= dom (vf0(#)(x`|Z) + uf0(#)(y`|Z))
  proof
A98: [' a,b '] = [.a,b.] by A2,INTEGRA5:def 3;
A99: dom (vf0(#)(x`|Z) + uf0(#)(y`|Z))
    = dom (vf0(#)(x`|Z)) /\ dom (uf0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom vf0 /\ dom (x`|Z)) /\ dom (uf0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom vf0 /\ dom (x`|Z)) /\ (dom uf0 /\ dom (y`|Z)) by VALUED_1:def 4
    .= dom vf0 /\ ((dom (x`|Z)) /\ (dom uf0 /\ dom (y`|Z))) by XBOOLE_1:16
    .= dom vf0 /\ ((Z) /\ ((dom (y`|Z)) /\ dom uf0)) by A2,FDIFF_1:def 7
    .= dom vf0 /\ (Z /\ (Z /\ dom uf0)) by A2,FDIFF_1:def 7
    .= dom vf0 /\ ((Z /\ Z) /\ dom uf0) by XBOOLE_1:16
    .= (dom vf0 /\ dom uf0) /\ Z by XBOOLE_1:16;
    [.a,b.] c= dom vf0 /\ dom uf0 by A74,A84,XBOOLE_1:19;
    hence thesis by A2,A98,A99,XBOOLE_1:19;
  end;
  reconsider a,b as Real;
A100: (uf0(#)(x`|Z) - vf0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A101: (vf0(#)(x`|Z) + uf0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A2;
A102: (uf0(#)(x`|Z) - vf0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
A103: (vf0(#)(x`|Z) + uf0(#)(y`|Z))|[' a,b '] is bounded by A1,A2;
  integral(r(#)f,C) = integral( r(#)(uf0(#)(x`|Z)) - r(#)(vf0(#)(y`|Z)),a,b )
  + integral( r(#)(vf0(#)(x`|Z)) + r(#)(uf0(#)(y`|Z)),a,b )*<i>
    by A35,A61,A48,A22,A5,A1,A2,A4,Def4
  .= integral(r(#)(uf0(#)(x`|Z) - vf0(#)(y`|Z)),a,b )
  + integral(r(#)(vf0(#)(x`|Z)) + r(#)(uf0(#)(y`|Z)),a,b )*<i> by RFUNCT_1:18
  .= integral(r(#)(uf0(#)(x`|Z) - vf0(#)(y`|Z)),a,b )
  + integral(r(#)(vf0(#)(x`|Z) + uf0(#)(y`|Z)),a,b )*<i> by RFUNCT_1:16
  .= r*integral(uf0(#)(x`|Z) - vf0(#)(y`|Z),a,b )
  + integral(r(#)(vf0(#)(x`|Z) + uf0(#)(y`|Z)),a,b )*<i>
  by A2,A94,A100,A102,INTEGRA6:10
  .= r*integral(uf0(#)(x`|Z) - vf0(#)(y`|Z),a,b )
  + r*integral(vf0(#)(x`|Z) + uf0(#)(y`|Z),a,b )*<i>
  by A2,A97,A101,A103,INTEGRA6:10
  .= r*(integral(uf0(#)(x`|Z) - vf0(#)(y`|Z),a,b )
  + integral(vf0(#)(x`|Z) + uf0(#)(y`|Z),a,b )*<i>)
  .= r*integral(f,C) by A1,A2,A3,Def4;
  hence thesis;
end;

begin :: Complex Integral of Complex Curve's Connection

theorem
  for f be PartFunc of COMPLEX,COMPLEX, C,C1,C2 be C1-curve, a,b,d be Real
  st rng C c= dom f & f is_integrable_on C & f is_bounded_on C &
  a <= b & dom C = [.a,b.] & d in [.a,b.] &
  dom C1 = [.a,d.] & dom C2 = [.d,b.] &
  (for t st t in dom C1 holds C.t = C1.t) &
  (for t st t in dom C2 holds C.t = C2.t) holds
  integral(f,C) = integral(f,C1) + integral(f,C2)
proof
  let f be PartFunc of COMPLEX,COMPLEX,
  C,C1,C2 be C1-curve,
  a,b,d be Real such that
A1: rng C c= dom f & f is_integrable_on C & f is_bounded_on C &
  a <= b & dom C = [.a,b.] & d in [.a,b.] &
  dom C1 = [.a,d.] & dom C2 =[.d,b.] &
  (for t st t in dom C1 holds C.t = C1.t) &
  (for t st t in dom C2 holds C.t = C2.t);
A2: a <= d & d <= b by A1,XXREAL_1:1;
  consider a0,b0 be Real, x,y be PartFunc of REAL,REAL,
  Z be Subset of REAL such that
A3: a0 <= b0 & [.a0,b0.]=dom C & [.a0,b0.] c= dom x & [.a0,b0.] c= dom y &
  Z is open & [.a0,b0.] c= Z & x is_differentiable_on Z &
  y is_differentiable_on Z & x`|Z is continuous & y`|Z is continuous &
  C = (x+<i>(#)y) | [.a0,b0.] by Def3;
A4: a0 = a & b0 = b
  proof
    thus a0 = inf [.a0,b0.] by A3,XXREAL_2:25
    .= a by A1,A3,XXREAL_2:25;
    thus b0 = sup [.a0,b0.] by A3,XXREAL_2:29
    .= b by A1,A3,XXREAL_2:29;
  end;
  consider u0, v0 be PartFunc of REAL,REAL such that
A5: u0=(Re f)* (R2-to-C) *<:x,y:> & v0=(Im f)* (R2-to-C) *<:x,y:> &
  integral(f,x,y,a,b,Z)
  = integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i> by Def2;
  consider a1,b1 be Real,
  x1,y1 be PartFunc of REAL,REAL,
  Z1 be Subset of REAL such that
A6: a1 <= b1 & [.a1,b1.]=dom C1 & [.a1,b1.] c= dom x1 & [.a1,b1.] c= dom y1
  & Z1 is open & [.a1,b1.] c= Z1 & x1 is_differentiable_on Z1 &
  y1 is_differentiable_on Z1 & x1`|Z1 is continuous &
  y1`|Z1 is continuous &
  C1 = (x1+<i>(#)y1) | [.a1,b1.] by Def3;
A7: a1 = a & b1 = d
  proof
    thus a1 = inf [.a1,b1.] by A6,XXREAL_2:25
    .= a by A2,A1,A6,XXREAL_2:25;
    thus b1 = sup [.a1,b1.] by A6,XXREAL_2:29
    .= d by A2,A1,A6,XXREAL_2:29;
  end;
A8: rng C1 c= dom f
  proof
A9: [.a,d.] c= [.a,b.] by A2,XXREAL_1:34;
    for y0 be object st y0 in rng C1 holds y0 in rng C
    proof
      let y0 be object such that
A10:  y0 in rng C1;
      consider x0 be object such that
A11:  x0 in dom C1 & y0 = C1.x0 by A10,FUNCT_1:def 3;
      C1.x0 = C.x0 by A1,A11;
      hence thesis by A1,A9,A11,FUNCT_1:3;
    end;then
    rng C1 c= rng C;
    hence thesis by A1;
  end;
  consider a2,b2 be Real,
  x2,y2 be PartFunc of REAL,REAL,
  Z2 be Subset of REAL such that
A12: a2 <= b2 & [.a2,b2.]=dom C2 & [.a2,b2.] c= dom x2 & [.a2,b2.] c= dom y2 &
  Z2 is open & [.a2,b2.] c= Z2 &
  x2 is_differentiable_on Z2 & y2 is_differentiable_on Z2 &
  x2`|Z2 is continuous & y2`|Z2 is continuous &
  C2 = (x2+<i>(#)y2) | [.a2,b2.] by Def3;
A13: a2 = d & b2 = b
  proof
    thus a2 = inf [.a2,b2.] by A12,XXREAL_2:25
    .= d by A2,A1,A12,XXREAL_2:25;
    thus b2 = sup [.a2,b2.] by A12,XXREAL_2:29
    .= b by A2,A1,A12,XXREAL_2:29;
  end;
  rng C2 c= dom f
  proof
A14: [.d,b.] c= [.a,b.] by A2,XXREAL_1:34;
    for y0 be object st y0 in rng C2 holds y0 in rng C
    proof
      let y0 be object such that
A15:  y0 in rng C2;
      consider x0 be object such that
A16:  x0 in dom C2 & y0 = C2.x0 by A15,FUNCT_1:def 3;
      C2.x0 = C.x0 by A1,A16;
      hence thesis by A1,A14,A16,FUNCT_1:3;
    end;then
    rng C2 c= rng C;
    hence thesis by A1;
  end;then
A17: integral(f,C2) = integral(f,x2,y2,d,b,Z2) by A12,A13,Def4;
A18: [' a,b '] = [.a,b.] by A1,INTEGRA5:def 3;
A19: [' a,b '] c= dom u0
  proof
    for x0 be object st x0 in [.a,b.] holds x0 in dom u0
    proof
      let x0 be object such that
A20:  x0 in [.a,b.];
A21:  C.x0 in rng C by A3,A4,A20,FUNCT_1:3;
A22:  x0 in dom x & x0 in dom y by A3,A4,A20;
A23:  x0 in dom x /\ dom y by A3,A4,A20,XBOOLE_0:def 4;then
A24:  x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A23,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A25:  R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A22,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A3,A4,A20,XBOOLE_0:def 4;
      then
A26:  x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A27:  [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A28:  x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A20,A3,A4,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A26,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A27,A28,Def1
      .= (R2-to-C).R2 by A23,FUNCT_3:48; then
      (R2-to-C).R2 in dom f by A1,A21;then
      (R2-to-C).R2 in dom (Re f) by COMSEQ_3:def 3;then
      R2 in dom ((Re f)* (R2-to-C)) by A25,FUNCT_1:11;
      hence thesis by A5,A24,FUNCT_1:11;
    end;
    hence thesis by A18;
  end;
A29: [' a,b '] c= dom v0
  proof
    for x0 be object st x0 in [.a,b.] holds x0 in dom v0
    proof
      let x0 be object such that
A30:  x0 in [.a,b.];
A31:  C.x0 in rng C by A3,A4,A30,FUNCT_1:3;
A32:  x0 in dom x & x0 in dom y by A3,A4,A30;
A33:  x0 in dom x /\ dom y by A3,A4,A30,XBOOLE_0:def 4;then
A34:  x0 in dom <:x,y:> by FUNCT_3:def 7;
      set R2 = <:x,y:>.x0;
      reconsider xx0 = x.x0, yx0 = y.x0 as Element of REAL by XREAL_0:def 1;
      R2 = [xx0,yx0] by A33,FUNCT_3:48;then
      R2 in [:REAL,REAL:] by ZFMISC_1:def 2;then
A35:  R2 in dom (R2-to-C) by FUNCT_2:def 1;
      x0 in dom (<i>(#)y) by A32,VALUED_1:def 5;then
      x0 in dom x /\ dom (<i>(#)y) by A3,A4,A30,XBOOLE_0:def 4; then
A36:  x0 in dom (x+(<i>(#)y)) by VALUED_1:def 1;
A37:  [xx0,yx0] in [:REAL,REAL:] by ZFMISC_1:def 2;
A38:  x.x0 = [x.x0,y.x0]`1 & y.x0 = [x.x0,y.x0]`2;
      C.x0 = (x+<i>(#)y).x0 by A30,A3,A4,FUNCT_1:49
      .= x.x0+(<i>(#)y).x0 by A36,VALUED_1:def 1
      .= x.x0+<i>*y.x0 by VALUED_1:6
      .= (R2-to-C).([xx0,yx0]) by A37,A38,Def1
      .= (R2-to-C).R2 by A33,FUNCT_3:48; then
      (R2-to-C).R2 in dom f by A1,A31;then
      (R2-to-C).R2 in dom (Im f) by COMSEQ_3:def 4;then
      R2 in dom ((Im f)* (R2-to-C)) by A35,FUNCT_1:11;
      hence thesis by A5,A34,FUNCT_1:11;
    end;
    hence thesis by A18;
  end;
A39: (u0(#)(x`|Z) - v0(#)(y`|Z)) is_integrable_on [' a,b '] &
  (v0(#)(x`|Z) + u0(#)(y`|Z)) is_integrable_on [' a,b '] by A1,A3;
A40: (u0(#)(x`|Z) - v0(#)(y`|Z))|[' a,b '] is bounded &
  (v0(#)(x`|Z) + u0(#)(y`|Z))|[' a,b '] is bounded by A1,A3;
A41: [' a,b '] c= dom (u0(#)(x`|Z) - v0(#)(y`|Z))
  proof
A42: dom (u0(#)(x`|Z) - v0(#)(y`|Z))
    = dom (u0(#)(x`|Z)) /\ dom (v0(#)(y`|Z)) by VALUED_1:12
    .= (dom u0 /\ dom(x`|Z)) /\ dom (v0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom u0 /\ dom(x`|Z)) /\ (dom v0 /\ dom(y`|Z)) by VALUED_1:def 4
    .= (dom u0 /\ Z) /\ (dom v0 /\ dom(y`|Z)) by A3,FDIFF_1:def 7
    .= (dom u0 /\ Z) /\ (dom v0 /\ Z) by A3,FDIFF_1:def 7
    .= dom u0 /\ (Z /\ (dom v0 /\ Z)) by XBOOLE_1:16
    .= dom u0 /\ ((Z /\ Z) /\ dom v0) by XBOOLE_1:16
    .= (dom u0 /\ dom v0) /\ Z by XBOOLE_1:16;
A43: [' a,b '] c= dom u0 /\ dom v0 by A19,A29,XBOOLE_1:19;
    [' a,b '] c= Z by A1,A3,INTEGRA5:def 3;
    hence thesis by A42,A43,XBOOLE_1:19;
  end;
A44: [' a,b '] c= dom (v0(#)(x`|Z) + u0(#)(y`|Z))
  proof
A45: dom (v0(#)(x`|Z) + u0(#)(y`|Z))
    = dom (v0(#)(x`|Z)) /\ dom (u0(#)(y`|Z)) by VALUED_1:def 1
    .= (dom v0 /\ dom(x`|Z)) /\ dom (u0(#)(y`|Z)) by VALUED_1:def 4
    .= (dom v0 /\ dom(x`|Z)) /\ (dom u0 /\ dom(y`|Z)) by VALUED_1:def 4
    .= (dom v0 /\ Z) /\ (dom u0 /\ dom(y`|Z)) by A3,FDIFF_1:def 7
    .= (dom v0 /\ Z) /\ (dom u0 /\ Z) by A3,FDIFF_1:def 7
    .= dom v0 /\ (Z /\ (dom u0 /\ Z)) by XBOOLE_1:16
    .= dom v0 /\ ((Z /\ Z) /\ dom u0) by XBOOLE_1:16
    .= (dom v0 /\ dom u0) /\ Z by XBOOLE_1:16;
A46: [' a,b '] c= dom v0 /\ dom u0 by A19,A29,XBOOLE_1:19;
    [' a,b '] c= Z by A1,A3,INTEGRA5:def 3;
    hence thesis by A45,A46,XBOOLE_1:19;
  end;
A47: integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,d )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,d )*<i>
  = integral( f,x,y,a,d,Z ) by Def2,A5;
A48: integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,d,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,d,b )*<i>
  = integral( f,x,y,d,b,Z ) by Def2,A5;
A49: integral( f,x,y,a,d,Z ) = integral( f,x1,y1,a,d,Z1 )
  proof
    reconsider Z3 = Z /\ Z1 as Subset of REAL;
    reconsider ZZ=Z, ZZ1= Z1 as Subset of R^1 by TOPMETR:17;
    ZZ is open & ZZ1 is open by A3,A6,BORSUK_5:39; then
    ZZ /\ ZZ1 is open by TOPS_1:11; then
A50: Z3 is open by BORSUK_5:39;
A51: [.a,d.] c= [.a,b.] by A2,XXREAL_1:34;then
A52: [.a,d.] c= dom x & [.a,d.] c= dom y by A3,A4;
A53: x| [.a,d.] = x1| [.a,d.]
    proof
A54:  dom (x| [.a,d.]) = (dom x) /\ [.a,d.] by RELAT_1:61
      .= [.a,d.] by A3,A4,A51,XBOOLE_1:1,28
      .= (dom x1) /\ [.a,d.] by A6,A7,XBOOLE_1:28
      .= dom (x1| [.a,d.]) by RELAT_1:61;
      for x0 be object st x0 in dom (x| [.a,d.])
      holds (x| [.a,d.]).x0 = (x1| [.a,d.]).x0
      proof
        let x0 be object such that
A55:    x0 in dom (x| [.a,d.]);
A56:    dom (x| [.a,d.]) = (dom x) /\ [.a,d.] by RELAT_1:61
        .= [.a,d.] by A51,A3,A4,XBOOLE_1:1,28;
        [.a,d.] c= (dom x1) /\ dom y1 by A6,A7,XBOOLE_1:19;then
        x0 in (dom x1) /\ dom y1 by A55,A56; then
        x0 in (dom x1) /\ dom (<i>(#)y1) by VALUED_1:def 5;then
A57:    x0 in dom (x1+<i>(#)y1) by VALUED_1:def 1;
        [.a,d.] c= (dom x) /\ dom y by A52,XBOOLE_1:19;then
        x0 in (dom x) /\ dom y by A55,A56;then
        x0 in (dom x) /\ dom (<i>(#)y) by VALUED_1:def 5;then
A58:    x0 in dom (x+<i>(#)y) by VALUED_1:def 1;
        reconsider t = x0 as Element of REAL by A55;
A59:    C.t = C1.t by A1,A55,A56;
A60:    C.t = (x+<i>(#)y).t by A3,A4,A51,A55,A56,FUNCT_1:49;
A61:    C1.t = (x1+<i>(#)y1).t by A6,A7,A55,A56,FUNCT_1:49;
A62:    (x1+<i>(#)y1).t = x1.t+(<i>(#)y1).t by A57,VALUED_1:def 1
        .= x1.t+<i>*y1.t by VALUED_1:6;
A63:    (x+<i>(#)y).t = x.t+(<i>(#)y).t by A58,VALUED_1:def 1
        .= x.t+<i>*y.t by VALUED_1:6;
        thus (x| [.a,d.]).x0 = x.x0 by A55,FUNCT_1:47
        .= x1.x0 by A59,A60,A61,A62,A63,COMPLEX1:77
        .= (x1| [.a,d.]).x0 by A56,A55,FUNCT_1:49;
      end;
      hence thesis by A54,FUNCT_1:2;
    end;
A64: y| [.a,d.] = y1| [.a,d.]
    proof
A65:  dom (y| [.a,d.]) = (dom y) /\ [.a,d.] by RELAT_1:61
      .= [.a,d.] by A3,A4,A51,XBOOLE_1:1,28
      .= (dom y1) /\ [.a,d.] by A6,A7,XBOOLE_1:28
      .= dom (y1| [.a,d.]) by RELAT_1:61;
      for x0 be object st x0 in dom (y| [.a,d.])
      holds (y| [.a,d.]).x0 = (y1| [.a,d.]).x0
      proof
        let x0 be object such that
A66:    x0 in dom (y| [.a,d.]);
A67:    dom (y| [.a,d.]) = (dom y) /\ [.a,d.] by RELAT_1:61
        .= [.a,d.] by A3,A4,A51,XBOOLE_1:1,28;
        [.a,d.] c= (dom x1) /\ dom y1 by A6,A7,XBOOLE_1:19;then
        x0 in (dom x1) /\ dom y1 by A66,A67;then
        x0 in (dom x1) /\ dom (<i>(#)y1) by VALUED_1:def 5;then
A68:    x0 in dom (x1+<i>(#)y1) by VALUED_1:def 1;
        [.a,d.] c= (dom x) /\ dom y by A52,XBOOLE_1:19;then
        x0 in (dom x) /\ dom y by A66,A67;then
        x0 in (dom x) /\ dom (<i>(#)y) by VALUED_1:def 5;then
A69:    x0 in dom (x+<i>(#)y) by VALUED_1:def 1;
        reconsider t = x0 as Element of REAL by A66;
A70:    C.t = C1.t by A1,A66,A67;
A71:    C.t = (x+<i>(#)y).t by A3,A4,A51,A66,A67,FUNCT_1:49;
A72:    C1.t = (x1+<i>(#)y1).t by A6,A7,A66,A67,FUNCT_1:49;
A73:    (x1+<i>(#)y1).t = x1.t+(<i>(#)y1).t by A68,VALUED_1:def 1
        .= x1.t+<i>*y1.t by VALUED_1:6;
A74:    (x+<i>(#)y).t = x.t+(<i>(#)y).t by A69,VALUED_1:def 1
        .= x.t+<i>*y.t by VALUED_1:6;
        thus (y| [.a,d.]).x0 = y.x0 by A66,FUNCT_1:47
        .= y1.x0 by A70,A71,A72,A73,A74,COMPLEX1:77
        .= (y1| [.a,d.]).x0 by A67,A66,FUNCT_1:49;
      end;
      hence thesis by A65,FUNCT_1:2;
    end;
A75: [.a,d.] c= Z by A3,A4,A51;then
A76: [.a,d.] c= Z3 by A6,A7,XBOOLE_1:19;
A77: rng ((x+<i>(#)y) | [.a,d.]) c= dom f
    proof
        let y0 be object such that
A78:    y0 in rng ((x+<i>(#)y) | [.a,d.]);
        consider x0 be object such that
A79:    x0 in dom ((x+<i>(#)y) | [.a,d.])
        & y0 = ((x+<i>(#)y) | [.a,d.]).x0 by A78,FUNCT_1:def 3;
A80:    x0 in (dom (x+<i>(#)y)) /\ [.a,d.] by A79,RELAT_1:61;
        (dom (x+<i>(#)y)) /\ [.a,d.] c= (dom (x+<i>(#)y)) /\ [.a,b.]
        by A2,XBOOLE_1:26,XXREAL_1:34;then
        x0 in (dom (x+<i>(#)y)) /\ [.a,b.] by A80;then
A81:    x0 in dom ((x+<i>(#)y) | [.a,b.]) by RELAT_1:61; then
A82:    ((x+<i>(#)y) | [.a,b.]).x0 in rng ((x+<i>(#)y) | [.a,b.])
        by FUNCT_1:3;
        ((x+<i>(#)y) | [.a,d.]).x0 = (x+<i>(#)y).x0 by A79,FUNCT_1:47
        .= ((x+<i>(#)y) | [.a,b.]).x0 by A81,FUNCT_1:47;
        hence thesis by A1,A3,A79,A82;
    end;
A83: rng ((x1+<i>(#)y1) | [.a,d.]) c= dom f
    proof
        let y0 be object such that
A84:    y0 in rng ((x1+<i>(#)y1) | [.a,d.]);
        consider x0 be object such that
A85:    x0 in dom ((x1+<i>(#)y1) | [.a,d.])
        & y0 = ((x1+<i>(#)y1) | [.a,d.]).x0 by A84,FUNCT_1:def 3;
        x0 in (dom (x1+<i>(#)y1)) /\ [.a,d.] by A85,RELAT_1:61;
        then
A86:    x0 in [.a,d.] by XBOOLE_0:def 4;then
    x0 in [.a,b.] by A51;
        then x0 in (dom x) /\ (dom y) by A3,A4,XBOOLE_0:def 4;then
        x0 in ((dom x) /\ (dom y)) /\ [.a,b.] by A51,A86,XBOOLE_0:def 4;
        then
        x0 in ((dom x) /\ dom (<i>(#)y)) /\ [.a,b.] by VALUED_1:def 5;
        then
        x0 in (dom (x+<i>(#)y)) /\ [.a,b.] by VALUED_1:def 1;then
        x0 in dom ((x+<i>(#)y) | [.a,b.]) by RELAT_1:61; then
A87:    ((x+<i>(#)y) | [.a,b.]).x0 in rng ((x+<i>(#)y) | [.a,b.])
        by FUNCT_1:3;
        reconsider t = x0 as Element of REAL by A85;
A88:    C.t = (x+<i>(#)y).t by A3,A4,A51,A86,FUNCT_1:49;
A89:    C1.t = (x1+<i>(#)y1).t by A6,A7,A86,FUNCT_1:49;
        ((x1+<i>(#)y1) | [.a,d.]).x0 = (x1+<i>(#)y1).x0 by A85,FUNCT_1:47
        .= (x+<i>(#)y).x0 by A1,A86,A88,A89
        .= ((x+<i>(#)y) | [.a,b.]).x0 by A51,A86,FUNCT_1:49;
        hence thesis by A1,A3,A85,A87;
    end;
A90: x is_differentiable_on Z3 &
    y is_differentiable_on Z3 by A3,A50,FDIFF_1:26,XBOOLE_1:17;
A91: x1 is_differentiable_on Z3 &
    y1 is_differentiable_on Z3 by A6,A50,FDIFF_1:26,XBOOLE_1:17;
A92: [.a,d.] c= dom x & [.a,d.] c= dom y by A3,A4,A51;
    hence integral(f,x,y,a,d,Z)
    = integral(f,x,y,a,d,Z3) by A3,A6,A7,A50,A77,A76,Lm1,XBOOLE_1:17
    .= integral(f,x1,y1,a,d,Z3)
    by A6,A7,A50,A53,A64,A75,A77,A83,A90,A91,A92,Lm2,XBOOLE_1:19
    .= integral(f,x1,y1,a,d,Z1) by A6,A7,A50,A76,A83,Lm1,XBOOLE_1:17;
  end;
A93: integral( f,x,y,d,b,Z ) = integral( f,x2,y2,d,b,Z2 )
  proof
    reconsider Z3 = Z /\ Z2 as Subset of REAL;
    reconsider ZZ=Z, ZZ1= Z2 as Subset of R^1 by TOPMETR:17;
    ZZ is open & ZZ1 is open by A3,A12,BORSUK_5:39; then
    ZZ /\ ZZ1 is open by TOPS_1:11; then
A94: Z3 is open by BORSUK_5:39;
A95: [.d,b.] c= [.a,b.] by A2,XXREAL_1:34;then
A96: [.d,b.] c= dom x & [.d,b.] c= dom y by A3,A4;
A97: x| [.d,b.] = x2| [.d,b.]
    proof
A98: dom (x| [.d,b.]) = (dom x) /\ [.d,b.] by RELAT_1:61
      .= [.d,b.] by A3,A4,A95,XBOOLE_1:1,28
      .= (dom x2) /\ [.d,b.] by A12,A13,XBOOLE_1:28
      .= dom (x2| [.d,b.]) by RELAT_1:61;
      for x0 be object st x0 in dom (x| [.d,b.])
      holds (x| [.d,b.]).x0 = (x2| [.d,b.]).x0
      proof
        let x0 be object such that
A99:   x0 in dom (x| [.d,b.]);
A100:   dom (x| [.d,b.]) = (dom x) /\ [.d,b.] by RELAT_1:61
        .= [.d,b.] by A3,A4,A95,XBOOLE_1:1,28;
        [.d,b.] c= (dom x2) /\ dom y2 by A12,A13,XBOOLE_1:19;then
        x0 in (dom x2) /\ dom y2 by A99,A100; then
        x0 in (dom x2) /\ dom (<i>(#)y2) by VALUED_1:def 5;then
A101:   x0 in dom (x2+<i>(#)y2) by VALUED_1:def 1;
        [.d,b.] c= (dom x) /\ dom y by A96,XBOOLE_1:19;then
        x0 in (dom x) /\ dom y by A99,A100; then
        x0 in (dom x) /\ dom (<i>(#)y) by VALUED_1:def 5;then
A102:   x0 in dom (x+<i>(#)y) by VALUED_1:def 1;
        reconsider t = x0 as Element of REAL by A99;
A103:   C.t = C2.t by A1,A99,A100;
A104:   C.t = (x+<i>(#)y).t by A3,A4,A95,A99,A100,FUNCT_1:49;
A105:   C2.t = (x2+<i>(#)y2).t by A12,A13,A99,A100,FUNCT_1:49;
A106:   (x2+<i>(#)y2).t = x2.t+(<i>(#)y2).t by A101,VALUED_1:def 1
        .= x2.t+<i>*y2.t by VALUED_1:6;
A107:   (x+<i>(#)y).t = x.t+(<i>(#)y).t by A102,VALUED_1:def 1
        .= x.t+<i>*y.t by VALUED_1:6;
        thus (x| [.d,b.]).x0 = x.x0 by A99,FUNCT_1:47
        .= x2.x0 by A103,A104,A105,A106,A107,COMPLEX1:77
        .= (x2| [.d,b.]).x0 by A99,A100,FUNCT_1:49;
      end;
      hence thesis by A98,FUNCT_1:2;
    end;
A108: y| [.d,b.] = y2| [.d,b.]
    proof
A109: dom (y| [.d,b.]) = (dom y) /\ [.d,b.] by RELAT_1:61
      .= [.d,b.] by A3,A4,A95,XBOOLE_1:1,28
      .= (dom y2) /\ [.d,b.] by A12,A13,XBOOLE_1:28
      .= dom (y2| [.d,b.]) by RELAT_1:61;
      for x0 be object st x0 in dom (y| [.d,b.])
      holds (y| [.d,b.]).x0 = (y2| [.d,b.]).x0
      proof
        let x0 be object such that
A110:   x0 in dom (y| [.d,b.]);
A111:   dom (y| [.d,b.]) = (dom y) /\ [.d,b.] by RELAT_1:61
        .= [.d,b.] by A3,A4,A95,XBOOLE_1:1,28;
        [.d,b.] c= (dom x2) /\ dom y2 by A12,A13,XBOOLE_1:19;then
        x0 in (dom x2) /\ dom y2 by A110,A111;then
        x0 in (dom x2) /\ dom (<i>(#)y2) by VALUED_1:def 5;then
A112:   x0 in dom (x2+<i>(#)y2) by VALUED_1:def 1;
        [.d,b.] c= (dom x) /\ dom y by A96,XBOOLE_1:19;then
        x0 in (dom x) /\ dom y by A110,A111;then
        x0 in (dom x) /\ dom (<i>(#)y) by VALUED_1:def 5;then
A113:   x0 in dom (x+<i>(#)y) by VALUED_1:def 1;
        reconsider t = x0 as Element of REAL by A110;
A114:   C.t = C2.t by A1,A110,A111;
A115:   C.t = (x+<i>(#)y).t by A3,A4,A95,A110,A111,FUNCT_1:49;
A116:   C2.t = (x2+<i>(#)y2).t by A12,A13,A110,A111,FUNCT_1:49;
A117:   (x2+<i>(#)y2).t = x2.t+(<i>(#)y2).t by A112,VALUED_1:def 1
        .= x2.t+<i>*y2.t by VALUED_1:6;
A118:   (x+<i>(#)y).t = x.t+(<i>(#)y).t by A113,VALUED_1:def 1
        .= x.t+<i>*y.t by VALUED_1:6;
        thus (y| [.d,b.]).x0 = y.x0 by A110,FUNCT_1:47
        .= y2.x0 by A114,A115,A116,A117,A118,COMPLEX1:77
        .= (y2| [.d,b.]).x0 by A111,A110,FUNCT_1:49;
      end;
      hence thesis by A109,FUNCT_1:2;
    end;
A119: [.d,b.] c= Z by A3,A4,A95;then
A120: [.d,b.] c= Z3 by A12,A13,XBOOLE_1:19;
A121: rng ((x+<i>(#)y) | [.d,b.]) c= dom f
    proof
        let y0 be object such that
A122:   y0 in rng ((x+<i>(#)y) | [.d,b.]);
        consider x0 be object such that
A123:   x0 in dom ((x+<i>(#)y) | [.d,b.]) &
        y0 = ((x+<i>(#)y) | [.d,b.]).x0 by A122,FUNCT_1:def 3;
A124:   x0 in (dom (x+<i>(#)y)) /\ [.d,b.] by A123,RELAT_1:61;
        (dom (x+<i>(#)y)) /\ [.d,b.] c= (dom (x+<i>(#)y)) /\ [.a,b.]
        by A2,XBOOLE_1:26,XXREAL_1:34;then
        x0 in (dom (x+<i>(#)y)) /\ [.a,b.] by A124;then
A125:   x0 in dom ((x+<i>(#)y) | [.a,b.]) by RELAT_1:61;then
A126:   ((x+<i>(#)y) | [.a,b.]).x0 in rng ((x+<i>(#)y) | [.a,b.])
        by FUNCT_1:3;
        ((x+<i>(#)y) | [.d,b.]).x0 = (x+<i>(#)y).x0 by A123,FUNCT_1:47
        .= ((x+<i>(#)y) | [.a,b.]).x0 by A125,FUNCT_1:47;
        hence thesis by A1,A3,A123,A126;
    end;
A127: rng ((x2+<i>(#)y2) | [.d,b.]) c= dom f
    proof
        let y0 be object such that
A128:   y0 in rng ((x2+<i>(#)y2) | [.d,b.]);
        consider x0 be object such that
A129:   x0 in dom ((x2+<i>(#)y2) | [.d,b.]) &
        y0 = ((x2+<i>(#)y2) | [.d,b.]).x0 by A128,FUNCT_1:def 3;
        x0 in (dom (x2+<i>(#)y2)) /\ [.d,b.] by A129,RELAT_1:61;
        then
A130:   x0 in [.d,b.] by XBOOLE_0:def 4;then
   x0 in [.a,b.] by A95;
        then x0 in (dom x) /\ (dom y) by A3,A4,XBOOLE_0:def 4;then
        x0 in ((dom x) /\ (dom y)) /\ [.a,b.] by A95,A130,XBOOLE_0:def 4;
        then
        x0 in ((dom x) /\ dom (<i>(#)y)) /\ [.a,b.] by VALUED_1:def 5;
        then
        x0 in (dom (x+<i>(#)y)) /\ [.a,b.] by VALUED_1:def 1;then
        x0 in dom ((x+<i>(#)y) | [.a,b.]) by RELAT_1:61;then
A131:   ((x+<i>(#)y) | [.a,b.]).x0 in rng ((x+<i>(#)y) | [.a,b.])
        by FUNCT_1:3;
        reconsider t = x0 as Element of REAL by A129;
A132:   C.t = (x+<i>(#)y).t by A3,A4,A95,A130,FUNCT_1:49;
A133:   C2.t = (x2+<i>(#)y2).t by A12,A13,A130,FUNCT_1:49;
        ((x2+<i>(#)y2) | [.d,b.]).x0 = (x2+<i>(#)y2).x0 by A129,FUNCT_1:47
        .= (x+<i>(#)y).x0 by A1,A130,A132,A133
        .= ((x+<i>(#)y) | [.a,b.]).x0 by A95,A130,FUNCT_1:49;
        hence thesis by A1,A3,A129,A131;
    end;
A134: x is_differentiable_on Z3 &
    y is_differentiable_on Z3 by A3,A94,FDIFF_1:26,XBOOLE_1:17;
A135: x2 is_differentiable_on Z3 &
    y2 is_differentiable_on Z3 by A12,A94,FDIFF_1:26,XBOOLE_1:17;
A136: [.d,b.] c= dom x & [.d,b.] c= dom y by A3,A4,A95;
    hence integral(f,x,y,d,b,Z) = integral(f,x,y,d,b,Z3)
    by A3,A12,A13,A94,A120,A121,Lm1,XBOOLE_1:17
    .= integral(f,x2,y2,d,b,Z3)
    by Lm2,A12,A13,A94,A97,A108,A119,A121,A127,A134,A135,A136,XBOOLE_1:19
    .= integral(f,x2,y2,d,b,Z2) by A12,A13,A94,A120,A127,Lm1,XBOOLE_1:17;
  end;
  thus integral(f,C) = integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i> by A1,A3,A5,Def4
  .= integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,d )
  + integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,d,b )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,b )*<i>
  by A1,A18,A39,A40,A41,INTEGRA6:17
  .= integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,a,d )
  + integral( u0(#)(x`|Z) - v0(#)(y`|Z) ,d,b )
  +(integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,a,d )
  + integral( v0(#)(x`|Z) + u0(#)(y`|Z) ,d,b ))*<i>
  by A1,A18,A39,A40,A44,INTEGRA6:17
  .= integral( f,x1,y1,a,d,Z1 ) + integral( f,x,y,d,b,Z ) by A49,A48,A47
  .= integral(f,C1) + integral(f,C2) by A6,A7,A8,A17,Def4,A93;
end;