afvect0.miz
begin
definition
let IT be non
empty
AffinStruct;
::
AFVECT0:def1
attr IT is
WeakAffVect-like means
:
Def1: (for a,b,c be
Element of IT st (a,b)
// (c,c) holds a
= b) & (for a,b,c,d,p,q be
Element of IT st (a,b)
// (p,q) & (c,d)
// (p,q) holds (a,b)
// (c,d)) & (for a,b,c be
Element of IT holds ex d be
Element of IT st (a,b)
// (c,d)) & (for a,b,c,a9,b9,c9 be
Element of IT st (a,b)
// (a9,b9) & (a,c)
// (a9,c9) holds (b,c)
// (b9,c9)) & (for a,c be
Element of IT holds ex b be
Element of IT st (a,b)
// (b,c)) & for a,b,c,d be
Element of IT st (a,b)
// (c,d) holds (a,c)
// (b,d);
end
registration
cluster
strict
WeakAffVect-like for non
trivial
AffinStruct;
existence
proof
set AFV = the
strict
AffVect;
reconsider AS = AFV as non
empty
AffinStruct;
A1: (for a,b,c be
Element of AS holds ex d be
Element of AS st (a,b)
// (c,d)) & for a,b,c,a9,b9,c9 be
Element of AS st (a,b)
// (a9,b9) & (a,c)
// (a9,c9) holds (b,c)
// (b9,c9) by
TDGROUP: 16;
A2: (for a,c be
Element of AS holds ex b be
Element of AS st (a,b)
// (b,c)) & for a,b,c,d be
Element of AS st (a,b)
// (c,d) holds (a,c)
// (b,d) by
TDGROUP: 16;
(for a,b,c be
Element of AS st (a,b)
// (c,c) holds a
= b) & for a,b,c,d,p,q be
Element of AS st (a,b)
// (p,q) & (c,d)
// (p,q) holds (a,b)
// (c,d) by
TDGROUP: 16;
then AS is
WeakAffVect-like by
A1,
A2;
hence thesis;
end;
end
definition
mode
WeakAffVect is
WeakAffVect-like non
trivial
AffinStruct;
end
registration
cluster
AffVect-like ->
WeakAffVect-like for non
empty
AffinStruct;
coherence by
TDGROUP:def 5;
end
reserve AFV for
WeakAffVect;
reserve a,b,c,d,e,f,a9,b9,c9,d9,f9,p,q,r,o,x99 for
Element of AFV;
theorem ::
AFVECT0:1
Th1: (a,b)
// (a,b)
proof
ex d st (a,b)
// (b,d) by
Def1;
hence thesis by
Def1;
end;
theorem ::
AFVECT0:2
(a,a)
// (a,a) by
Th1;
theorem ::
AFVECT0:3
Th3: (a,b)
// (c,d) implies (c,d)
// (a,b)
proof
assume
A1: (a,b)
// (c,d);
(c,d)
// (c,d) by
Th1;
hence thesis by
A1,
Def1;
end;
theorem ::
AFVECT0:4
Th4: (a,b)
// (a,c) implies b
= c
proof
assume (a,b)
// (a,c);
then (a,a)
// (b,c) by
Def1;
then (b,c)
// (a,a) by
Th3;
hence thesis by
Def1;
end;
theorem ::
AFVECT0:5
Th5: (a,b)
// (c,d) & (a,b)
// (c,d9) implies d
= d9
proof
assume (a,b)
// (c,d) & (a,b)
// (c,d9);
then (c,d)
// (a,b) & (c,d9)
// (a,b) by
Th3;
then (c,d)
// (c,d9) by
Def1;
hence thesis by
Th4;
end;
theorem ::
AFVECT0:6
Th6: for a, b holds (a,a)
// (b,b)
proof
let a, b;
consider p such that
A1: (a,a)
// (b,p) by
Def1;
(b,p)
// (a,a) by
A1,
Th3;
hence thesis by
A1,
Def1;
end;
theorem ::
AFVECT0:7
Th7: (a,b)
// (c,d) implies (b,a)
// (d,c)
proof
assume
A1: (a,b)
// (c,d);
(a,a)
// (c,c) by
Th6;
hence thesis by
A1,
Def1;
end;
theorem ::
AFVECT0:8
(a,b)
// (c,d) & (a,c)
// (b9,d) implies b
= b9
proof
assume that
A1: (a,b)
// (c,d) and
A2: (a,c)
// (b9,d);
(a,c)
// (b,d) by
A1,
Def1;
then (b,d)
// (a,c) by
Th3;
then
A3: (d,b)
// (c,a) by
Th7;
(b9,d)
// (a,c) by
A2,
Th3;
then (d,b9)
// (c,a) by
Th7;
then (d,b)
// (d,b9) by
A3,
Def1;
hence thesis by
Th4;
end;
theorem ::
AFVECT0:9
(b,c)
// (b9,c9) & (a,d)
// (b,c) & (a,d9)
// (b9,c9) implies d
= d9
proof
assume that
A1: (b,c)
// (b9,c9) and
A2: (a,d)
// (b,c) and
A3: (a,d9)
// (b9,c9);
(b9,c9)
// (b,c) by
A1,
Th3;
then (a,d)
// (b9,c9) by
A2,
Def1;
then (a,d)
// (a,d9) by
A3,
Def1;
hence thesis by
Th4;
end;
theorem ::
AFVECT0:10
(a,b)
// (a9,b9) & (c,d)
// (b,a) & (c,d9)
// (b9,a9) implies d
= d9
proof
assume that
A1: (a,b)
// (a9,b9) and
A2: (c,d)
// (b,a) and
A3: (c,d9)
// (b9,a9);
(a9,b9)
// (a,b) by
A1,
Th3;
then (b9,a9)
// (b,a) by
Th7;
then (c,d)
// (b9,a9) by
A2,
Def1;
then (c,d)
// (c,d9) by
A3,
Def1;
hence thesis by
Th4;
end;
theorem ::
AFVECT0:11
(a,b)
// (a9,b9) & (c,d)
// (c9,d9) & (b,f)
// (c,d) & (b9,f9)
// (c9,d9) implies (a,f)
// (a9,f9)
proof
assume that
A1: (a,b)
// (a9,b9) and
A2: (c,d)
// (c9,d9) and
A3: (b,f)
// (c,d) and
A4: (b9,f9)
// (c9,d9);
(b9,f9)
// (c,d) by
A2,
A4,
Def1;
then
A5: (b,f)
// (b9,f9) by
A3,
Def1;
(b,a)
// (b9,a9) by
A1,
Th7;
hence thesis by
A5,
Def1;
end;
theorem ::
AFVECT0:12
Th12: (a,b)
// (a9,b9) & (a,c)
// (c9,b9) implies (b,c)
// (c9,a9)
proof
assume that
A1: (a,b)
// (a9,b9) and
A2: (a,c)
// (c9,b9);
consider d such that
A3: (c9,b9)
// (a9,d) by
Def1;
(a9,d)
// (c9,b9) by
A3,
Th3;
then (a,c)
// (a9,d) by
A2,
Def1;
then
A4: (b,c)
// (b9,d) by
A1,
Def1;
(c9,a9)
// (b9,d) by
A3,
Def1;
hence thesis by
A4,
Def1;
end;
definition
let AFV;
let a, b;
::
AFVECT0:def2
pred
MDist a,b means (a,b)
// (b,a) & a
<> b;
irreflexivity ;
symmetry by
Th3;
end
theorem ::
AFVECT0:13
ex a, b st a
<> b & not
MDist (a,b)
proof
consider p, q such that
A1: p
<> q by
STRUCT_0:def 10;
now
consider r such that
A2: (p,r)
// (r,q) by
Def1;
A3:
now
A4:
now
assume
MDist (p,r);
then
A5: (p,r)
// (r,p);
(r,q)
// (p,r) by
A2,
Th3;
then (q,r)
// (r,p) by
Th7;
then (p,r)
// (q,r) by
A5,
Def1;
hence thesis by
A1,
Th4,
Th7;
end;
assume p
<> r;
hence thesis by
A4;
end;
now
assume
A6: p
= r;
then (r,q)
// (p,p) by
A2,
Th3;
hence thesis by
A1,
A6,
Def1;
end;
hence thesis by
A3;
end;
hence thesis;
end;
theorem ::
AFVECT0:14
MDist (a,b) &
MDist (a,c) implies b
= c or
MDist (b,c)
proof
assume that
A1:
MDist (a,b) and
A2:
MDist (a,c);
A3: (a,b)
// (b,a) by
A1;
A4: (a,c)
// (c,a) by
A2;
consider d such that
A5: (c,a)
// (b,d) by
Def1;
(b,d)
// (c,a) by
A5,
Th3;
then (a,c)
// (b,d) by
A4,
Def1;
then
A6: (b,c)
// (a,d) by
A3,
Def1;
(c,b)
// (a,d) by
A5,
Def1;
then (b,c)
// (c,b) by
A6,
Def1;
hence thesis;
end;
theorem ::
AFVECT0:15
MDist (a,b) & (a,b)
// (c,d) implies
MDist (c,d)
proof
assume that
A1:
MDist (a,b) and
A2: (a,b)
// (c,d);
A3: (a,b)
// (b,a) by
A1;
A4: (c,d)
// (a,b) by
A2,
Th3;
then (d,c)
// (b,a) by
Th7;
then (d,c)
// (a,b) by
A3,
Def1;
then (c,d)
// (d,c) by
A4,
Def1;
then c
<> d implies thesis;
hence thesis by
A1,
A2,
Def1;
end;
definition
let AFV;
let a, b, c;
::
AFVECT0:def3
pred
Mid a,b,c means
:
Def3: (a,b)
// (b,c);
end
theorem ::
AFVECT0:16
Th16:
Mid (a,b,c) implies
Mid (c,b,a)
proof
assume
Mid (a,b,c);
then (a,b)
// (b,c);
then (b,a)
// (c,b) by
Th7;
then (c,b)
// (b,a) by
Th3;
hence thesis;
end;
theorem ::
AFVECT0:17
Mid (a,b,b) iff a
= b by
Def1,
Th6;
theorem ::
AFVECT0:18
Th18:
Mid (a,b,a) iff a
= b or
MDist (a,b) by
Th6;
theorem ::
AFVECT0:19
Th19: ex b st
Mid (a,b,c)
proof
consider b such that
A1: (a,b)
// (b,c) by
Def1;
Mid (a,b,c) by
A1;
hence thesis;
end;
theorem ::
AFVECT0:20
Th20:
Mid (a,b,c) &
Mid (a,b9,c) implies b
= b9 or
MDist (b,b9)
proof
assume that
A1:
Mid (a,b,c) and
A2:
Mid (a,b9,c);
A3: (a,b)
// (b,c) by
A1;
consider d such that
A4: (b9,c)
// (b,d) by
Def1;
A5: (b,d)
// (b9,c) by
A4,
Th3;
then (b,b9)
// (d,c) by
Def1;
then
A6: (b9,b)
// (c,d) by
Th7;
(a,b9)
// (b9,c) by
A2;
then (a,b9)
// (b,d) by
A5,
Def1;
then (b,b9)
// (c,d) by
A3,
Def1;
then (b,b9)
// (b9,b) by
A6,
Def1;
hence thesis;
end;
theorem ::
AFVECT0:21
Th21: ex c st
Mid (a,b,c)
proof
consider c such that
A1: (a,b)
// (b,c) by
Def1;
Mid (a,b,c) by
A1;
hence thesis;
end;
theorem ::
AFVECT0:22
Th22:
Mid (a,b,c) &
Mid (a,b,c9) implies c
= c9
proof
assume that
A1:
Mid (a,b,c) and
A2:
Mid (a,b,c9);
(a,b)
// (b,c9) by
A2;
then
A3: (b,c9)
// (a,b) by
Th3;
(a,b)
// (b,c) by
A1;
then (b,c)
// (a,b) by
Th3;
then (b,c)
// (b,c9) by
A3,
Def1;
hence thesis by
Th4;
end;
theorem ::
AFVECT0:23
Th23:
Mid (a,b,c) &
MDist (b,b9) implies
Mid (a,b9,c)
proof
assume that
A1:
Mid (a,b,c) and
A2:
MDist (b,b9);
A3: (b,b9)
// (b9,b) by
A2;
(a,b)
// (b,c) by
A1;
then
A4: (b,a)
// (c,b) by
Th7;
consider d such that
A5: (b9,b)
// (c,d) by
Def1;
(c,d)
// (b9,b) by
A5,
Th3;
then (b,b9)
// (c,d) by
A3,
Def1;
then
A6: (a,b9)
// (b,d) by
A4,
Def1;
(b9,c)
// (b,d) by
A5,
Def1;
then (a,b9)
// (b9,c) by
A6,
Def1;
hence thesis;
end;
theorem ::
AFVECT0:24
Th24:
Mid (a,b,c) &
Mid (a,b9,c9) &
MDist (b,b9) implies c
= c9
proof
assume that
A1:
Mid (a,b,c) and
A2:
Mid (a,b9,c9) and
A3:
MDist (b,b9);
Mid (a,b9,c) by
A1,
A3,
Th23;
hence thesis by
A2,
Th22;
end;
theorem ::
AFVECT0:25
Th25:
Mid (a,p,a9) &
Mid (b,p,b9) implies (a,b)
// (b9,a9)
proof
assume that
A1:
Mid (a,p,a9) and
A2:
Mid (b,p,b9);
consider d such that
A3: (b9,p)
// (a9,d) by
Def1;
(a,p)
// (p,a9) by
A1;
then
A4: (p,a)
// (a9,p) by
Th7;
(b,p)
// (p,b9) by
A2;
then
A5: (p,b)
// (b9,p) by
Th7;
(a9,d)
// (b9,p) by
A3,
Th3;
then (p,b)
// (a9,d) by
A5,
Def1;
then
A6: (a,b)
// (p,d) by
A4,
Def1;
(b9,a9)
// (p,d) by
A3,
Def1;
hence thesis by
A6,
Def1;
end;
theorem ::
AFVECT0:26
Mid (a,p,a9) &
Mid (b,q,b9) &
MDist (p,q) implies (a,b)
// (b9,a9)
proof
assume that
A1:
Mid (a,p,a9) and
A2:
Mid (b,q,b9) and
A3:
MDist (p,q);
Mid (a,q,a9) by
A1,
A3,
Th23;
hence thesis by
A2,
Th25;
end;
definition
let AFV;
let a, b;
::
AFVECT0:def4
func
PSym (a,b) ->
Element of AFV means
:
Def4:
Mid (b,a,it );
correctness by
Th21,
Th22;
end
theorem ::
AFVECT0:27
(
PSym (p,a))
= b iff (a,p)
// (p,b) by
Def3,
Def4;
theorem ::
AFVECT0:28
Th28: (
PSym (p,a))
= a iff a
= p or
MDist (a,p)
proof
A1:
now
assume a
= p or
MDist (a,p);
then
Mid (a,p,a) by
Th18;
hence (
PSym (p,a))
= a by
Def4;
end;
now
assume (
PSym (p,a))
= a;
then
Mid (a,p,a) by
Def4;
hence a
= p or
MDist (a,p);
end;
hence thesis by
A1;
end;
theorem ::
AFVECT0:29
Th29: (
PSym (p,(
PSym (p,a))))
= a
proof
Mid (a,p,(
PSym (p,a))) by
Def4;
then
Mid ((
PSym (p,a)),p,a) by
Th16;
hence thesis by
Def4;
end;
theorem ::
AFVECT0:30
Th30: (
PSym (p,a))
= (
PSym (p,b)) implies a
= b
proof
assume
A1: (
PSym (p,a))
= (
PSym (p,b));
(
PSym (p,(
PSym (p,a))))
= a by
Th29;
hence thesis by
A1,
Th29;
end;
theorem ::
AFVECT0:31
ex a st (
PSym (p,a))
= b
proof
(
PSym (p,(
PSym (p,b))))
= b by
Th29;
hence thesis;
end;
theorem ::
AFVECT0:32
Th32: (a,b)
// ((
PSym (p,b)),(
PSym (p,a)))
proof
Mid (a,p,(
PSym (p,a))) &
Mid (b,p,(
PSym (p,b))) by
Def4;
hence thesis by
Th25;
end;
theorem ::
AFVECT0:33
Th33: (a,b)
// (c,d) iff ((
PSym (p,a)),(
PSym (p,b)))
// ((
PSym (p,c)),(
PSym (p,d)))
proof
A1:
now
assume
A2: ((
PSym (p,a)),(
PSym (p,b)))
// ((
PSym (p,c)),(
PSym (p,d)));
(d,c)
// ((
PSym (p,c)),(
PSym (p,d))) by
Th32;
then (d,c)
// ((
PSym (p,a)),(
PSym (p,b))) by
A2,
Def1;
then
A3: (c,d)
// ((
PSym (p,b)),(
PSym (p,a))) by
Th7;
(a,b)
// ((
PSym (p,b)),(
PSym (p,a))) by
Th32;
hence (a,b)
// (c,d) by
A3,
Def1;
end;
now
A4: ((
PSym (p,b)),(
PSym (p,a)))
// (a,b) by
Th3,
Th32;
assume
A5: (a,b)
// (c,d);
((
PSym (p,d)),(
PSym (p,c)))
// (c,d) by
Th3,
Th32;
then ((
PSym (p,d)),(
PSym (p,c)))
// (a,b) by
A5,
Def1;
then ((
PSym (p,b)),(
PSym (p,a)))
// ((
PSym (p,d)),(
PSym (p,c))) by
A4,
Def1;
hence ((
PSym (p,a)),(
PSym (p,b)))
// ((
PSym (p,c)),(
PSym (p,d))) by
Th7;
end;
hence thesis by
A1;
end;
theorem ::
AFVECT0:34
MDist (a,b) iff
MDist ((
PSym (p,a)),(
PSym (p,b))) by
Th30,
Th33;
theorem ::
AFVECT0:35
Th35:
Mid (a,b,c) iff
Mid ((
PSym (p,a)),(
PSym (p,b)),(
PSym (p,c))) by
Th33;
theorem ::
AFVECT0:36
Th36: (
PSym (p,a))
= (
PSym (q,a)) iff p
= q or
MDist (p,q)
proof
A1:
now
assume
A2:
MDist (p,q);
Mid (a,p,(
PSym (p,a))) &
Mid (a,q,(
PSym (q,a))) by
Def4;
hence (
PSym (p,a))
= (
PSym (q,a)) by
A2,
Th24;
end;
now
assume
A3: (
PSym (p,a))
= (
PSym (q,a));
Mid (a,p,(
PSym (p,a))) &
Mid (a,q,(
PSym (q,a))) by
Def4;
hence p
= q or
MDist (p,q) by
A3,
Th20;
end;
hence thesis by
A1;
end;
theorem ::
AFVECT0:37
Th37: (
PSym (q,(
PSym (p,(
PSym (q,a))))))
= (
PSym ((
PSym (q,p)),a))
proof
Mid ((
PSym (q,a)),p,(
PSym (p,(
PSym (q,a))))) by
Def4;
then
Mid ((
PSym (q,(
PSym (q,a)))),(
PSym (q,p)),(
PSym (q,(
PSym (p,(
PSym (q,a))))))) by
Th35;
then (
PSym (q,(
PSym (p,(
PSym (q,a))))))
= (
PSym ((
PSym (q,p)),(
PSym (q,(
PSym (q,a)))))) by
Def4;
hence thesis by
Th29;
end;
theorem ::
AFVECT0:38
(
PSym (p,(
PSym (q,a))))
= (
PSym (q,(
PSym (p,a)))) iff p
= q or
MDist (p,q) or
MDist (q,(
PSym (p,q)))
proof
A1:
now
assume (
PSym (p,(
PSym (q,a))))
= (
PSym (q,(
PSym (p,a))));
then (
PSym (p,(
PSym (q,(
PSym (p,a))))))
= (
PSym (q,a)) by
Th29;
then (
PSym ((
PSym (p,q)),a))
= (
PSym (q,a)) by
Th37;
then q
= (
PSym (p,q)) or
MDist (q,(
PSym (p,q))) by
Th36;
then
A2:
Mid (q,p,q) or
MDist (q,(
PSym (p,q))) by
Def4;
hence p
= q or
MDist (q,p) or
MDist (q,(
PSym (p,q)));
thus p
= q or
MDist (p,q) or
MDist (q,(
PSym (p,q))) by
A2,
Th18;
end;
now
assume p
= q or
MDist (p,q) or
MDist (q,(
PSym (p,q)));
then
Mid (q,p,q) or
MDist (q,(
PSym (p,q))) by
Th18;
then (
PSym ((
PSym (p,q)),a))
= (
PSym (q,a)) by
Def4,
Th36;
then (
PSym (p,(
PSym (q,(
PSym (p,a))))))
= (
PSym (q,a)) by
Th37;
hence (
PSym (p,(
PSym (q,a))))
= (
PSym (q,(
PSym (p,a)))) by
Th29;
end;
hence thesis by
A1;
end;
theorem ::
AFVECT0:39
Th39: (
PSym (p,(
PSym (q,(
PSym (r,a))))))
= (
PSym (r,(
PSym (q,(
PSym (p,a))))))
proof
(p,a)
// ((
PSym (r,a)),(
PSym (r,p))) & ((
PSym (q,(
PSym (r,p)))),(
PSym (q,(
PSym (r,a)))))
// ((
PSym (r,a)),(
PSym (r,p))) by
Th3,
Th32;
then
A1: (p,a)
// ((
PSym (q,(
PSym (r,p)))),(
PSym (q,(
PSym (r,a))))) by
Def1;
(p,a)
// ((
PSym (p,a)),(
PSym (p,p))) & ((
PSym (q,(
PSym (p,p)))),(
PSym (q,(
PSym (p,a)))))
// ((
PSym (p,a)),(
PSym (p,p))) by
Th3,
Th32;
then
A2: (p,a)
// ((
PSym (q,(
PSym (p,p)))),(
PSym (q,(
PSym (p,a))))) by
Def1;
((
PSym (q,p)),(
PSym (r,p)))
// ((
PSym (r,(
PSym (r,p)))),(
PSym (r,(
PSym (q,p))))) by
Th32;
then ((
PSym (q,p)),(
PSym (r,p)))
// (p,(
PSym (r,(
PSym (q,p))))) by
Th29;
then
A3: (p,(
PSym (r,(
PSym (q,p)))))
// ((
PSym (q,p)),(
PSym (r,p))) by
Th3;
((
PSym (q,(
PSym (r,p)))),p)
// ((
PSym (q,p)),(
PSym (q,(
PSym (q,(
PSym (r,p))))))) by
Th32;
then ((
PSym (q,(
PSym (r,p)))),p)
// ((
PSym (q,p)),(
PSym (r,p))) by
Th29;
then ((
PSym (q,(
PSym (r,p)))),p)
// (p,(
PSym (r,(
PSym (q,p))))) by
A3,
Def1;
then
Mid ((
PSym (q,(
PSym (r,p)))),p,(
PSym (r,(
PSym (q,p)))));
then (
PSym (p,(
PSym (q,(
PSym (r,p))))))
= (
PSym (r,(
PSym (q,p)))) by
Def4;
then
A4: (
PSym (p,(
PSym (q,(
PSym (r,p))))))
= (
PSym (r,(
PSym (q,(
PSym (p,p)))))) by
Th28;
((
PSym (r,(
PSym (q,(
PSym (p,a)))))),(
PSym (r,(
PSym (q,(
PSym (p,p)))))))
// ((
PSym (q,(
PSym (p,p)))),(
PSym (q,(
PSym (p,a))))) by
Th3,
Th32;
then
A5: ((
PSym (r,(
PSym (q,(
PSym (p,a)))))),(
PSym (r,(
PSym (q,(
PSym (p,p)))))))
// (p,a) by
A2,
Def1;
((
PSym (p,(
PSym (q,(
PSym (r,a)))))),(
PSym (p,(
PSym (q,(
PSym (r,p)))))))
// ((
PSym (q,(
PSym (r,p)))),(
PSym (q,(
PSym (r,a))))) by
Th3,
Th32;
then ((
PSym (p,(
PSym (q,(
PSym (r,a)))))),(
PSym (p,(
PSym (q,(
PSym (r,p)))))))
// (p,a) by
A1,
Def1;
then ((
PSym (p,(
PSym (q,(
PSym (r,a)))))),(
PSym (p,(
PSym (q,(
PSym (r,p)))))))
// ((
PSym (r,(
PSym (q,(
PSym (p,a)))))),(
PSym (p,(
PSym (q,(
PSym (r,p))))))) by
A4,
A5,
Def1;
hence thesis by
Th4,
Th7;
end;
theorem ::
AFVECT0:40
ex d st (
PSym (a,(
PSym (b,(
PSym (c,p))))))
= (
PSym (d,p))
proof
consider e such that
A1:
Mid (a,e,c) by
Th19;
consider d such that
A2:
Mid (b,e,d) by
Th21;
c
= (
PSym (e,a)) by
A1,
Def4;
then (
PSym (c,(
PSym (d,p))))
= (
PSym ((
PSym (e,a)),(
PSym ((
PSym (e,b)),p)))) by
A2,
Def4
.= (
PSym ((
PSym (e,a)),(
PSym (e,(
PSym (b,(
PSym (e,p)))))))) by
Th37
.= (
PSym (e,(
PSym (a,(
PSym (e,(
PSym (e,(
PSym (b,(
PSym (e,p)))))))))))) by
Th37
.= (
PSym (e,(
PSym (a,(
PSym (b,(
PSym (e,p)))))))) by
Th29
.= (
PSym (e,(
PSym (e,(
PSym (b,(
PSym (a,p)))))))) by
Th39
.= (
PSym (b,(
PSym (a,p)))) by
Th29;
then (
PSym (d,p))
= (
PSym (c,(
PSym (b,(
PSym (a,p)))))) by
Th29;
hence thesis by
Th39;
end;
theorem ::
AFVECT0:41
ex c st (
PSym (a,(
PSym (c,p))))
= (
PSym (c,(
PSym (b,p))))
proof
consider c such that
A1:
Mid (a,c,b) by
Th19;
(
PSym (b,p))
= (
PSym ((
PSym (c,a)),p)) by
A1,
Def4
.= (
PSym (c,(
PSym (a,(
PSym (c,p)))))) by
Th37;
then (
PSym (c,(
PSym (b,p))))
= (
PSym (a,(
PSym (c,p)))) by
Th29;
hence thesis;
end;
definition
let AFV, o;
let a, b;
::
AFVECT0:def5
func
Padd (o,a,b) ->
Element of AFV means
:
Def5: (o,a)
// (b,it );
correctness by
Def1,
Th5;
end
notation
let AFV, o;
let a;
synonym
Pcom (o,a) for
PSym (o,a);
end
Lm1: (
Pcom (o,a))
= b iff (a,o)
// (o,b) by
Def4,
Def3;
definition
let AFV, o;
::
AFVECT0:def6
func
Padd (o) ->
BinOp of the
carrier of AFV means
:
Def6: for a, b holds (it
. (a,b))
= (
Padd (o,a,b));
existence
proof
deffunc
F(
Element of AFV,
Element of AFV) = (
Padd (o,$1,$2));
consider O be
BinOp of the
carrier of AFV such that
A1: for a, b holds (O
. (a,b))
=
F(a,b) from
BINOP_1:sch 4;
take O;
thus thesis by
A1;
end;
uniqueness
proof
set X = the
carrier of AFV;
let o1,o2 be
BinOp of the
carrier of AFV such that
A2: for a, b holds (o1
. (a,b))
= (
Padd (o,a,b)) and
A3: for a, b holds (o2
. (a,b))
= (
Padd (o,a,b));
for x be
Element of
[:X, X:] holds (o1
. x)
= (o2
. x)
proof
let x be
Element of
[:X, X:];
consider x1,x2 be
Element of X such that
A4: x
=
[x1, x2] by
DOMAIN_1: 1;
(o1
. x)
= (o1
. (x1,x2)) by
A4
.= (
Padd (o,x1,x2)) by
A2
.= (o2
. (x1,x2)) by
A3
.= (o2
. x) by
A4;
hence thesis;
end;
hence thesis by
FUNCT_2: 63;
end;
end
definition
let AFV, o;
::
AFVECT0:def7
func
Pcom (o) ->
UnOp of the
carrier of AFV means
:
Def7: for a holds (it
. a)
= (
Pcom (o,a));
existence
proof
deffunc
F(
Element of AFV) = (
Pcom (o,$1));
consider O be
UnOp of the
carrier of AFV such that
A1: for a holds (O
. a)
=
F(a) from
FUNCT_2:sch 4;
take O;
thus thesis by
A1;
end;
uniqueness
proof
set X = the
carrier of AFV;
let o1,o2 be
UnOp of the
carrier of AFV such that
A2: for a holds (o1
. a)
= (
Pcom (o,a)) and
A3: for a holds (o2
. a)
= (
Pcom (o,a));
for x be
Element of X holds (o1
. x)
= (o2
. x)
proof
let x be
Element of X;
(o1
. x)
= (
Pcom (o,x)) by
A2
.= (o2
. x) by
A3;
hence thesis;
end;
hence thesis by
FUNCT_2: 63;
end;
end
definition
let AFV, o;
::
AFVECT0:def8
func
GroupVect (AFV,o) ->
strict
addLoopStr equals
addLoopStr (# the
carrier of AFV, (
Padd o), o #);
correctness ;
end
registration
let AFV, o;
cluster (
GroupVect (AFV,o)) -> non
empty;
coherence ;
end
theorem ::
AFVECT0:42
the
carrier of (
GroupVect (AFV,o))
= the
carrier of AFV & the
addF of (
GroupVect (AFV,o))
= (
Padd o) & (
0. (
GroupVect (AFV,o)))
= o;
reserve a,b,c for
Element of (
GroupVect (AFV,o));
theorem ::
AFVECT0:43
for a,b be
Element of (
GroupVect (AFV,o)), a9,b9 be
Element of AFV st a
= a9 & b
= b9 holds (a
+ b)
= ((
Padd o)
. (a9,b9));
Lm2: (a
+ b)
= (b
+ a)
proof
reconsider a9 = a, b9 = b as
Element of AFV;
reconsider c9 = (a
+ b) as
Element of AFV;
c9
= (
Padd (o,a9,b9)) by
Def6;
then (o,a9)
// (b9,c9) by
Def5;
then (o,b9)
// (a9,c9) by
Def1;
then c9
= (
Padd (o,b9,a9)) by
Def5
.= (b
+ a) by
Def6;
hence thesis;
end;
Lm3: ((a
+ b)
+ c)
= (a
+ (b
+ c))
proof
reconsider a9 = a, b9 = b, c9 = c as
Element of AFV;
set p = (b
+ c), q = (a
+ b);
reconsider p9 = p, q9 = q as
Element of AFV;
reconsider x9 = (a
+ p), y9 = (q
+ c) as
Element of AFV;
consider x99 such that
A1: (x9,p9)
// (c9,x99) by
Def1;
x9
= (
Padd (o,a9,p9)) by
Def6;
then (o,a9)
// (p9,x9) by
Def5;
then
A2: (a9,o)
// (x9,p9) by
Th7;
(c9,x99)
// (x9,p9) by
A1,
Th3;
then
A3: (a9,o)
// (c9,x99) by
A2,
Def1;
q9
= (
Padd (o,a9,b9)) by
Def6;
then (o,a9)
// (b9,q9) by
Def5;
then (o,b9)
// (a9,q9) by
Def1;
then
A4: (a9,q9)
// (o,b9) by
Th3;
p9
= (
Padd (o,b9,c9)) by
Def6;
then (o,b9)
// (c9,p9) by
Def5;
then (c9,p9)
// (o,b9) by
Th3;
then (a9,q9)
// (c9,p9) by
A4,
Def1;
then
A5: (q9,o)
// (p9,x99) by
A3,
Def1;
(x9,c9)
// (p9,x99) by
A1,
Def1;
then (q9,o)
// (x9,c9) by
A5,
Def1;
then (o,q9)
// (c9,x9) by
Th7;
then
A6: (c9,x9)
// (o,q9) by
Th3;
y9
= (
Padd (o,q9,c9)) by
Def6;
then (o,q9)
// (c9,y9) by
Def5;
then (c9,y9)
// (o,q9) by
Th3;
then (c9,y9)
// (c9,x9) by
A6,
Def1;
hence thesis by
Th4;
end;
Lm4: (a
+ (
0. (
GroupVect (AFV,o))))
= a
proof
reconsider a9 = a as
Element of AFV;
reconsider x9 = (a
+ (
0. (
GroupVect (AFV,o)))) as
Element of AFV;
x9
= (
Padd (o,a9,o)) by
Def6;
then (o,a9)
// (o,x9) by
Def5;
hence thesis by
Th4;
end;
Lm5: (
GroupVect (AFV,o)) is
Abelian
add-associative
right_zeroed
proof
thus for a, b holds (a
+ b)
= (b
+ a) by
Lm2;
thus for a, b, c holds ((a
+ b)
+ c)
= (a
+ (b
+ c)) by
Lm3;
thus for a holds (a
+ (
0. (
GroupVect (AFV,o))))
= a by
Lm4;
end;
Lm6: (
GroupVect (AFV,o)) is
right_complementable
proof
let s be
Element of (
GroupVect (AFV,o));
reconsider s9 = s as
Element of AFV;
reconsider t = ((
Pcom o)
. s9) as
Element of (
GroupVect (AFV,o));
take t;
(
Pcom (o,o))
= o by
Th28;
then (o,s9)
// ((
Pcom (o,s9)),o) by
Th32;
then
A1: (
Padd (o,s9,(
Pcom (o,s9))))
= o by
Def5;
thus (s
+ t)
= ((
Padd o)
. (s9,(
Pcom (o,s9)))) by
Def7
.= (
0. (
GroupVect (AFV,o))) by
A1,
Def6;
end;
registration
let AFV, o;
cluster (
GroupVect (AFV,o)) ->
Abelian
add-associative
right_zeroed
right_complementable;
coherence by
Lm5,
Lm6;
end
theorem ::
AFVECT0:44
Th44: for a be
Element of (
GroupVect (AFV,o)), a9 be
Element of AFV st a
= a9 holds (
- a)
= ((
Pcom o)
. a9)
proof
let a be
Element of (
GroupVect (AFV,o)), a9 be
Element of AFV;
assume
A1: a
= a9;
reconsider aa = ((
Pcom o)
. a9) as
Element of (
GroupVect (AFV,o));
(
Pcom (o,o))
= o & (o,a9)
// ((
Pcom (o,a9)),(
Pcom (o,o))) by
Th28,
Th32;
then
A2: (
Padd (o,a9,(
Pcom (o,a9))))
= o by
Def5;
(a
+ aa)
= ((
Padd o)
. (a,(
Pcom (o,a9)))) by
Def7
.= (
0. (
GroupVect (AFV,o))) by
A1,
A2,
Def6;
hence thesis by
RLVECT_1:def 10;
end;
theorem ::
AFVECT0:45
(
0. (
GroupVect (AFV,o)))
= o;
reserve a,b for
Element of (
GroupVect (AFV,o));
theorem ::
AFVECT0:46
Th46: for a holds ex b st (b
+ b)
= a
proof
let a;
reconsider a99 = a as
Element of AFV;
consider b9 be
Element of AFV such that
A1: (o,b9)
// (b9,a99) by
Def1;
reconsider b = b9 as
Element of (
GroupVect (AFV,o));
a99
= (
Padd (o,b9,b9)) by
A1,
Def5
.= (b
+ b) by
Def6;
hence thesis;
end;
registration
let AFV, o;
cluster (
GroupVect (AFV,o)) ->
Two_Divisible;
coherence
proof
for a holds ex b st (b
+ b)
= a by
Th46;
hence thesis by
TDGROUP:def 1;
end;
end
reserve AFV for
AffVect,
o for
Element of AFV;
theorem ::
AFVECT0:47
Th47: for a be
Element of (
GroupVect (AFV,o)) st (a
+ a)
= (
0. (
GroupVect (AFV,o))) holds a
= (
0. (
GroupVect (AFV,o)))
proof
let a be
Element of (
GroupVect (AFV,o)) such that
A1: (a
+ a)
= (
0. (
GroupVect (AFV,o)));
reconsider a99 = a as
Element of AFV;
o
= (
Padd (o,a99,a99)) by
A1,
Def6;
then
A2: (o,a99)
// (a99,o) by
Def5;
(o,o)
// (o,o) by
Th1;
hence thesis by
A2,
TDGROUP: 16;
end;
registration
let AFV, o;
cluster (
GroupVect (AFV,o)) ->
Fanoian;
coherence
proof
for a be
Element of (
GroupVect (AFV,o)) st (a
+ a)
= (
0. (
GroupVect (AFV,o))) holds a
= (
0. (
GroupVect (AFV,o))) by
Th47;
hence thesis by
VECTSP_1:def 18;
end;
end
registration
cluster
strict non
trivial for
Uniquely_Two_Divisible_Group;
existence
proof
set X =
G_Real ;
X is non
trivial by
TDGROUP: 6;
hence thesis;
end;
end
definition
mode
Proper_Uniquely_Two_Divisible_Group is non
trivial
Uniquely_Two_Divisible_Group;
end
theorem ::
AFVECT0:48
(
GroupVect (AFV,o)) is
Proper_Uniquely_Two_Divisible_Group;
registration
let AFV, o;
cluster (
GroupVect (AFV,o)) -> non
trivial;
coherence ;
end
theorem ::
AFVECT0:49
Th49: for ADG be
Proper_Uniquely_Two_Divisible_Group holds (
AV ADG) is
AffVect
proof
let ADG be
Proper_Uniquely_Two_Divisible_Group;
ex a,b be
Element of ADG st a
<> b by
STRUCT_0:def 10;
hence thesis by
TDGROUP: 17;
end;
registration
let ADG be
Proper_Uniquely_Two_Divisible_Group;
cluster (
AV ADG) ->
AffVect-like non
trivial;
coherence by
Th49;
end
theorem ::
AFVECT0:50
Th50: for AFV be
strict
AffVect holds for o be
Element of AFV holds AFV
= (
AV (
GroupVect (AFV,o)))
proof
let AFV be
strict
AffVect;
let o be
Element of AFV;
set X = (
GroupVect (AFV,o));
now
let x,y be
object;
set xy =
[x, y];
A1:
now
set V = the
carrier of AFV;
assume
A2: xy
in the
CONGR of AFV;
set VV =
[:V, V:];
(xy
`2 )
= y;
then
A3: y
in VV by
A2,
MCART_1: 10;
then
A4: y
=
[(y
`1 ), (y
`2 )] by
MCART_1: 21;
(xy
`1 )
= x;
then
A5: x
in VV by
A2,
MCART_1: 10;
then
reconsider x1 = (x
`1 ), x2 = (x
`2 ), y1 = (y
`1 ), y2 = (y
`2 ) as
Element of AFV by
A3,
MCART_1: 10;
reconsider x19 = x1, x29 = x2, y19 = y1, y29 = y2 as
Element of X;
A6: x
=
[(x
`1 ), (x
`2 )] by
A5,
MCART_1: 21;
then
A7: (x1,x2)
// (y1,y2) by
A2,
A4,
ANALOAF:def 2;
(x19
# y29)
= (x29
# y19)
proof
reconsider z1 = (x19
# y29), z2 = (x29
# y19) as
Element of AFV;
z1
= (
Padd (o,x1,y2)) by
Def6;
then (o,x1)
// (y2,z1) by
Def5;
then (x1,o)
// (z1,y2) by
Th7;
then
A8: (o,x2)
// (y1,z1) by
A7,
Th12;
z2
= (
Padd (o,x2,y1)) by
Def6;
hence thesis by
A8,
Def5;
end;
hence
[x, y]
in (
CONGRD X) by
A6,
A4,
TDGROUP:def 2;
end;
now
set V = the
carrier of X;
assume
A9: xy
in (
CONGRD X);
set VV =
[:V, V:];
(xy
`2 )
= y;
then
A10: y
in VV by
A9,
MCART_1: 10;
then
A11: y
=
[(y
`1 ), (y
`2 )] by
MCART_1: 21;
(xy
`1 )
= x;
then
A12: x
in VV by
A9,
MCART_1: 10;
then
reconsider x19 = (x
`1 ), x29 = (x
`2 ), y19 = (y
`1 ), y29 = (y
`2 ) as
Element of X by
A10,
MCART_1: 10;
set z19 = (x19
# y29), z29 = (x29
# y19);
reconsider x1 = x19, x2 = x29, y1 = y19, y2 = y29 as
Element of AFV;
reconsider z1 = z19, z2 = z29 as
Element of AFV;
A13: z2
= (
Padd (o,x2,y1)) by
Def6;
z1
= (
Padd (o,x1,y2)) by
Def6;
then
A14: (o,x1)
// (y2,z1) by
Def5;
A15: x
=
[(x
`1 ), (x
`2 )] by
A12,
MCART_1: 21;
then z19
= z29 by
A9,
A11,
TDGROUP:def 2;
then (o,x2)
// (y1,z1) by
A13,
Def5;
then (x1,x2)
// (y1,y2) by
A14,
Th12;
hence xy
in the
CONGR of AFV by
A15,
A11,
ANALOAF:def 2;
end;
hence
[x, y]
in (
CONGRD X) iff
[x, y]
in the
CONGR of AFV by
A1;
end;
then the
carrier of (
AV X)
= the
carrier of AFV & (
CONGRD X)
= the
CONGR of AFV by
RELAT_1:def 2,
TDGROUP: 4;
hence thesis by
TDGROUP: 4;
end;
theorem ::
AFVECT0:51
for AS be
strict
AffinStruct holds (AS is
AffVect iff ex ADG be
Proper_Uniquely_Two_Divisible_Group st AS
= (
AV ADG))
proof
let AS be
strict
AffinStruct;
now
assume AS is
AffVect;
then
reconsider AS9 = AS as
AffVect;
set o = the
Element of AS9;
take ADG = (
GroupVect (AS9,o));
AS9
= (
AV ADG) by
Th50;
hence ex ADG be
Proper_Uniquely_Two_Divisible_Group st AS
= (
AV ADG);
end;
hence thesis;
end;
definition
let X,Y be non
empty
addLoopStr;
let f be
Function of the
carrier of X, the
carrier of Y;
::
AFVECT0:def9
pred f
is_Iso_of X,Y means f is
one-to-one & (
rng f)
= the
carrier of Y & for a,b be
Element of X holds (f
. (a
+ b))
= ((f
. a)
+ (f
. b)) & (f
. (
0. X))
= (
0. Y) & (f
. (
- a))
= (
- (f
. a));
end
definition
let X,Y be non
empty
addLoopStr;
::
AFVECT0:def10
pred X,Y
are_Iso means ex f be
Function of the
carrier of X, the
carrier of Y st f
is_Iso_of (X,Y);
end
reserve ADG for
Proper_Uniquely_Two_Divisible_Group;
reserve f for
Function of the
carrier of ADG, the
carrier of ADG;
theorem ::
AFVECT0:52
Th52: for o9 be
Element of ADG, o be
Element of (
AV ADG) st (for x be
Element of ADG holds (f
. x)
= (o9
+ x)) & o
= o9 holds for a,b be
Element of ADG holds (f
. (a
+ b))
= ((
Padd o)
. ((f
. a),(f
. b))) & (f
. (
0. ADG))
= (
0. (
GroupVect ((
AV ADG),o))) & (f
. (
- a))
= ((
Pcom o)
. (f
. a))
proof
let o9 be
Element of ADG, o be
Element of (
AV ADG);
assume that
A1: for x be
Element of ADG holds (f
. x)
= (o9
+ x) and
A2: o
= o9;
let a,b be
Element of ADG;
set a9 = (f
. a), b9 = (f
. b);
A3: (
AV ADG)
=
AffinStruct (# the
carrier of ADG, (
CONGRD ADG) #) by
TDGROUP:def 3;
then
reconsider a99 = a9, b99 = b9 as
Element of (
AV ADG);
thus (f
. (a
+ b))
= ((
Padd o)
. ((f
. a),(f
. b)))
proof
A4: ((
Padd o)
. ((f
. a),(f
. b)))
= (
Padd (o,a99,b99)) by
Def6;
then
reconsider c99 = ((
Padd o)
. ((f
. a),(f
. b))) as
Element of (
AV ADG);
reconsider c9 = c99 as
Element of ADG by
A3;
(o,a99)
// (b99,c99) by
A4,
Def5;
then
[
[o9, a9],
[b9, c9]]
in (
CONGRD ADG) by
A2,
A3,
ANALOAF:def 2;
then
A5: (o9
+ c9)
= (a9
+ b9) by
TDGROUP:def 2;
a9
= (o9
+ a) & b9
= (o9
+ b) by
A1;
then (o9
+ c9)
= (o9
+ ((a
+ o9)
+ b)) by
A5,
RLVECT_1:def 3
.= (o9
+ (o9
+ (a
+ b))) by
RLVECT_1:def 3;
then c9
= (o9
+ (a
+ b)) by
RLVECT_1: 8
.= (f
. (a
+ b)) by
A1;
hence thesis;
end;
(f
. (
0. ADG))
= (o9
+ (
0. ADG)) by
A1
.= (
0. (
GroupVect ((
AV ADG),o))) by
A2,
RLVECT_1: 4;
hence (f
. (
0. ADG))
= (
0. (
GroupVect ((
AV ADG),o)));
thus (f
. (
- a))
= ((
Pcom o)
. (f
. a))
proof
A6: ((
Pcom o)
. (f
. a))
= (
Pcom (o,a99)) by
Def7;
then
reconsider c99 = ((
Pcom o)
. (f
. a)) as
Element of (
AV ADG);
reconsider c9 = c99 as
Element of ADG by
A3;
(a99,o)
// (o,c99) by
A6,
Lm1;
then
[
[a9, o9],
[o9, c9]]
in (
CONGRD ADG) by
A2,
A3,
ANALOAF:def 2;
then (a9
+ c9)
= (o9
+ o9) by
TDGROUP:def 2;
then
A7: (o9
+ o9)
= ((o9
+ a)
+ c9) by
A1
.= (o9
+ (a
+ c9)) by
RLVECT_1:def 3;
(f
. (
- a))
= (o9
+ (
- a)) by
A1
.= ((c9
+ a)
+ (
- a)) by
A7,
RLVECT_1: 8
.= (c9
+ (a
+ (
- a))) by
RLVECT_1:def 3
.= (c9
+ (
0. ADG)) by
RLVECT_1: 5
.= c9 by
RLVECT_1: 4;
hence thesis;
end;
end;
theorem ::
AFVECT0:53
Th53: for o9 be
Element of ADG st (for b be
Element of ADG holds (f
. b)
= (o9
+ b)) holds f is
one-to-one
proof
let o9 be
Element of ADG such that
A1: for b be
Element of ADG holds (f
. b)
= (o9
+ b);
now
let x1,x2 be
object such that
A2: x1
in (
dom f) & x2
in (
dom f) and
A3: (f
. x1)
= (f
. x2);
reconsider x19 = x1, x29 = x2 as
Element of ADG by
A2,
FUNCT_2:def 1;
(o9
+ x29)
= (f
. x19) by
A1,
A3
.= (o9
+ x19) by
A1;
hence x1
= x2 by
RLVECT_1: 8;
end;
hence thesis by
FUNCT_1:def 4;
end;
theorem ::
AFVECT0:54
Th54: for o9 be
Element of ADG, o be
Element of (
AV ADG) st (for b be
Element of ADG holds (f
. b)
= (o9
+ b)) holds (
rng f)
= the
carrier of (
GroupVect ((
AV ADG),o))
proof
set X = the
carrier of ADG;
A1: X
= (
dom f) by
FUNCT_2:def 1;
let o9 be
Element of ADG, o be
Element of (
AV ADG) such that
A2: for b be
Element of ADG holds (f
. b)
= (o9
+ b);
now
let y be
object;
assume y
in X;
then
reconsider y9 = y as
Element of X;
set x9 = (y9
- o9);
(f
. x9)
= (o9
+ ((
- o9)
+ y9)) by
A2
.= ((o9
+ (
- o9))
+ y9) by
RLVECT_1:def 3
.= (y9
+ (
0. ADG)) by
RLVECT_1: 5
.= y by
RLVECT_1: 4;
hence y
in (
rng f) by
A1,
FUNCT_1:def 3;
end;
then
A3: X
c= (
rng f) by
TARSKI:def 3;
(
rng f)
c= X & X
= the
carrier of (
GroupVect ((
AV ADG),o)) by
RELAT_1:def 19,
TDGROUP: 4;
hence thesis by
A3,
XBOOLE_0:def 10;
end;
theorem ::
AFVECT0:55
for ADG be
Proper_Uniquely_Two_Divisible_Group, o9 be
Element of ADG, o be
Element of (
AV ADG) st o
= o9 holds (ADG,(
GroupVect ((
AV ADG),o)))
are_Iso
proof
let ADG be
Proper_Uniquely_Two_Divisible_Group, o9 be
Element of ADG, o be
Element of (
AV ADG) such that
A1: o
= o9;
set AS = (
AV ADG);
set X = the
carrier of ADG, Z = (
GroupVect (AS,o));
set T = the
carrier of (
GroupVect (AS,o));
deffunc
F(
Element of X) = (o9
+ $1);
consider g be
UnOp of X such that
A2: for a be
Element of X holds (g
. a)
=
F(a) from
FUNCT_2:sch 4;
X
= T by
TDGROUP: 4;
then
reconsider f = g as
Function of X, T;
A3:
now
let a,b be
Element of ADG;
reconsider fa = (f
. a) as
Element of (
AV ADG);
thus (f
. (a
+ b))
= ((f
. a)
+ (f
. b)) by
A1,
A2,
Th52;
thus (f
. (
0. ADG))
= (
0. Z) by
A1,
A2,
Th52;
thus (f
. (
- a))
= ((
Pcom o)
. fa) by
A1,
A2,
Th52
.= (
- (f
. a)) by
Th44;
end;
f is
one-to-one & (
rng f)
= T by
A2,
Th53,
Th54;
then f
is_Iso_of (ADG,Z) by
A3;
hence thesis;
end;