let G be non empty symmetric irreflexive RelStr ; :: thesis: for a, b, c, d being Element of G
for Z being Subset of G st Z = {a,b,c,d} & a,b,c,d are_mutually_different & [a,b] in the InternalRel of G & [b,c] in the InternalRel of G & [c,d] in the InternalRel of G & not [a,c] in the InternalRel of G & not [a,d] in the InternalRel of G & not [b,d] in the InternalRel of G holds
subrelstr Z embeds Necklace 4
let a, b, c, d be Element of G; :: thesis: for Z being Subset of G st Z = {a,b,c,d} & a,b,c,d are_mutually_different & [a,b] in the InternalRel of G & [b,c] in the InternalRel of G & [c,d] in the InternalRel of G & not [a,c] in the InternalRel of G & not [a,d] in the InternalRel of G & not [b,d] in the InternalRel of G holds
subrelstr Z embeds Necklace 4
let Z be Subset of G; :: thesis: ( Z = {a,b,c,d} & a,b,c,d are_mutually_different & [a,b] in the InternalRel of G & [b,c] in the InternalRel of G & [c,d] in the InternalRel of G & not [a,c] in the InternalRel of G & not [a,d] in the InternalRel of G & not [b,d] in the InternalRel of G implies subrelstr Z embeds Necklace 4 )
assume that
A1:
Z = {a,b,c,d}
and
A2:
a,b,c,d are_mutually_different
and
A3:
[a,b] in the InternalRel of G
and
A4:
[b,c] in the InternalRel of G
and
A5:
[c,d] in the InternalRel of G
and
A6:
not [a,c] in the InternalRel of G
and
A7:
not [a,d] in the InternalRel of G
and
A8:
not [b,d] in the InternalRel of G
; :: thesis: subrelstr Z embeds Necklace 4
set H = subrelstr Z;
set N4 = Necklace 4;
set IH = the InternalRel of (subrelstr Z);
set cH = the carrier of (subrelstr Z);
set IG = the InternalRel of G;
set X = {[a,a],[a,b],[b,a],[b,b],[a,c],[a,d],[b,c],[b,d]};
set Y = {[c,a],[c,b],[d,a],[d,b],[c,c],[c,d],[d,c],[d,d]};
A9:
the InternalRel of (subrelstr Z) = {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
proof
thus
the
InternalRel of
(subrelstr Z) c= {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
:: according to XBOOLE_0:def 10 :: thesis: {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]} c= the InternalRel of (subrelstr Z)proof
let x be
set ;
:: according to TARSKI:def 3 :: thesis: ( not x in the InternalRel of (subrelstr Z) or x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]} )
assume
x in the
InternalRel of
(subrelstr Z)
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
then A10:
x in the
InternalRel of
G |_2 the
carrier of
(subrelstr Z)
by YELLOW_0:def 14;
then A11:
(
x in the
InternalRel of
G &
x in [:the carrier of (subrelstr Z),the carrier of (subrelstr Z):] )
by XBOOLE_0:def 4;
the
carrier of
(subrelstr Z) = Z
by YELLOW_0:def 15;
then A12:
x in {[a,a],[a,b],[b,a],[b,b],[a,c],[a,d],[b,c],[b,d]} \/ {[c,a],[c,b],[d,a],[d,b],[c,c],[c,d],[d,c],[d,d]}
by A1, A11, Th3;
per cases
( x in {[a,a],[a,b],[b,a],[b,b],[a,c],[a,d],[b,c],[b,d]} or x in {[c,a],[c,b],[d,a],[d,b],[c,c],[c,d],[d,c],[d,d]} )
by A12, XBOOLE_0:def 3;
suppose A13:
x in {[a,a],[a,b],[b,a],[b,b],[a,c],[a,d],[b,c],[b,d]}
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}thus
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
:: thesis: verumproof
per cases
( x = [a,a] or x = [a,b] or x = [b,a] or x = [b,b] or x = [a,c] or x = [a,d] or x = [b,c] or x = [b,d] )
by A13, ENUMSET1:def 6;
suppose A14:
x = [a,a]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
not
[a,a] in the
InternalRel of
G
by NECKLACE:def 6;
hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A10, A14, XBOOLE_0:def 4;
:: thesis: verum end; suppose
x = [a,b]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose
x = [b,a]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose A15:
x = [b,b]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
not
[b,b] in the
InternalRel of
G
by NECKLACE:def 6;
hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A10, A15, XBOOLE_0:def 4;
:: thesis: verum end; suppose
x = [a,c]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A6, A10, XBOOLE_0:def 4;
:: thesis: verum end; suppose
x = [a,d]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A7, A10, XBOOLE_0:def 4;
:: thesis: verum end; suppose
x = [b,c]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose
x = [b,d]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A8, A10, XBOOLE_0:def 4;
:: thesis: verum end; end;
end; end; suppose A16:
x in {[c,a],[c,b],[d,a],[d,b],[c,c],[c,d],[d,c],[d,d]}
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}A17:
the
InternalRel of
G is_symmetric_in the
carrier of
G
by NECKLACE:def 4;
thus
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
:: thesis: verumproof
per cases
( x = [c,a] or x = [c,b] or x = [d,a] or x = [d,b] or x = [c,c] or x = [c,d] or x = [d,c] or x = [d,d] )
by A16, ENUMSET1:def 6;
suppose
x = [c,a]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A6, A11, A17, RELAT_2:def 3;
:: thesis: verum end; suppose
x = [c,b]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose
x = [d,a]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A7, A11, A17, RELAT_2:def 3;
:: thesis: verum end; suppose
x = [d,b]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A8, A11, A17, RELAT_2:def 3;
:: thesis: verum end; suppose A18:
x = [c,c]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
not
[c,c] in the
InternalRel of
G
by NECKLACE:def 6;
hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A10, A18, XBOOLE_0:def 4;
:: thesis: verum end; suppose
x = [c,d]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose
x = [d,c]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by ENUMSET1:def 4;
:: thesis: verum end; suppose A19:
x = [d,d]
;
:: thesis: x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
not
[d,d] in the
InternalRel of
G
by NECKLACE:def 6;
hence
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
by A10, A19, XBOOLE_0:def 4;
:: thesis: verum end; end;
end; end; end;
end;
let x be
set ;
:: according to TARSKI:def 3 :: thesis: ( not x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]} or x in the InternalRel of (subrelstr Z) )
assume A20:
x in {[a,b],[b,a],[b,c],[c,b],[c,d],[d,c]}
;
:: thesis: x in the InternalRel of (subrelstr Z)
end;
A30:
( a <> b & a <> c & a <> d & b <> c & b <> d & c <> d )
by A2, ZFMISC_1:def 6;
set g = 0 ,1 --> a,b;
set h = 2,3 --> c,d;
set f = (0 ,1 --> a,b) +* (2,3 --> c,d);
dom ((0 ,1 --> a,b) +* (2,3 --> c,d)) =
(dom (0 ,1 --> a,b)) \/ (dom (2,3 --> c,d))
by FUNCT_4:def 1
.=
{0 ,1} \/ (dom (2,3 --> c,d))
by FUNCT_4:65
.=
{0 ,1} \/ {2,3}
by FUNCT_4:65
.=
{0 ,1,2,3}
by ENUMSET1:45
;
then A31:
dom ((0 ,1 --> a,b) +* (2,3 --> c,d)) = the carrier of (Necklace 4)
by NECKLACE:2, NECKLACE:21;
A32:
rng (0 ,1 --> a,b) = {a,b}
by FUNCT_4:67;
A33:
rng (2,3 --> c,d) = {c,d}
by FUNCT_4:67;
A34:
not the carrier of (subrelstr Z) is empty
by A1, YELLOW_0:def 15;
A35:
dom (0 ,1 --> a,b) misses dom (2,3 --> c,d)
A37:
rng ((0 ,1 --> a,b) +* (2,3 --> c,d)) = the carrier of (subrelstr Z)
proof
rng ((0 ,1 --> a,b) +* (2,3 --> c,d)) = (rng (0 ,1 --> a,b)) \/ (rng (2,3 --> c,d))
by A35, NECKLACE:7;
then
rng ((0 ,1 --> a,b) +* (2,3 --> c,d)) = {a,b,c,d}
by A32, A33, ENUMSET1:45;
hence
rng ((0 ,1 --> a,b) +* (2,3 --> c,d)) = the
carrier of
(subrelstr Z)
by A1, YELLOW_0:def 15;
:: thesis: verum
end;
then reconsider f = (0 ,1 --> a,b) +* (2,3 --> c,d) as Function of (Necklace 4),(subrelstr Z) by A31, FUNCT_2:def 1, RELSET_1:11;
A38:
0 ,1 --> a,b is one-to-one
A43:
2,3 --> c,d is one-to-one
A48:
rng (0 ,1 --> a,b) misses rng (2,3 --> c,d)
proof
assume
not
rng (0 ,1 --> a,b) misses rng (2,3 --> c,d)
;
:: thesis: contradiction
then consider x being
set such that A49:
(
x in rng (0 ,1 --> a,b) &
x in rng (2,3 --> c,d) )
by XBOOLE_0:3;
( (
x = a or
x = b ) & (
x = c or
x = d ) )
by A32, A33, A49, TARSKI:def 2;
hence
contradiction
by A2, ZFMISC_1:def 6;
:: thesis: verum
end;
then A50:
f is one-to-one
by A38, A43, FUNCT_4:98;
for x, y being Element of (Necklace 4) holds
( [x,y] in the InternalRel of (Necklace 4) iff [(f . x),(f . y)] in the InternalRel of (subrelstr Z) )
proof
let x,
y be
Element of
(Necklace 4);
:: thesis: ( [x,y] in the InternalRel of (Necklace 4) iff [(f . x),(f . y)] in the InternalRel of (subrelstr Z) )
thus
(
[x,y] in the
InternalRel of
(Necklace 4) implies
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z) )
:: thesis: ( [(f . x),(f . y)] in the InternalRel of (subrelstr Z) implies [x,y] in the InternalRel of (Necklace 4) )proof
assume A51:
[x,y] in the
InternalRel of
(Necklace 4)
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)
per cases
( [x,y] = [0 ,1] or [x,y] = [1,0 ] or [x,y] = [1,2] or [x,y] = [2,1] or [x,y] = [2,3] or [x,y] = [3,2] )
by A51, ENUMSET1:def 4, NECKLA_2:2;
suppose
[x,y] = [0 ,1]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A52:
(
x = 0 &
y = 1 )
by ZFMISC_1:33;
then
(
x in {0 ,1} &
y in {0 ,1} )
by TARSKI:def 2;
then A53:
(
x in dom (0 ,1 --> a,b) &
y in dom (0 ,1 --> a,b) )
by FUNCT_4:65;
then A54:
f . x =
(0 ,1 --> a,b) . 0
by A35, A52, FUNCT_4:17
.=
a
by FUNCT_4:66
;
f . y =
(0 ,1 --> a,b) . 1
by A35, A52, A53, FUNCT_4:17
.=
b
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A54, ENUMSET1:def 4;
:: thesis: verum end; suppose
[x,y] = [1,0 ]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A55:
(
x = 1 &
y = 0 )
by ZFMISC_1:33;
then
(
x in {0 ,1} &
y in {0 ,1} )
by TARSKI:def 2;
then A56:
(
x in dom (0 ,1 --> a,b) &
y in dom (0 ,1 --> a,b) )
by FUNCT_4:65;
then A57:
f . x =
(0 ,1 --> a,b) . 1
by A35, A55, FUNCT_4:17
.=
b
by FUNCT_4:66
;
f . y =
(0 ,1 --> a,b) . 0
by A35, A55, A56, FUNCT_4:17
.=
a
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A57, ENUMSET1:def 4;
:: thesis: verum end; suppose
[x,y] = [1,2]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A58:
(
x = 1 &
y = 2 )
by ZFMISC_1:33;
then
(
x in {0 ,1} &
y in {2,3} )
by TARSKI:def 2;
then A59:
(
x in dom (0 ,1 --> a,b) &
y in dom (2,3 --> c,d) )
by FUNCT_4:65;
then A60:
f . x =
(0 ,1 --> a,b) . 1
by A35, A58, FUNCT_4:17
.=
b
by FUNCT_4:66
;
(0 ,1 --> a,b) +* (2,3 --> c,d) = (2,3 --> c,d) +* (0 ,1 --> a,b)
by A35, FUNCT_4:36;
then f . y =
(2,3 --> c,d) . 2
by A35, A58, A59, FUNCT_4:17
.=
c
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A60, ENUMSET1:def 4;
:: thesis: verum end; suppose
[x,y] = [2,1]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A61:
(
x = 2 &
y = 1 )
by ZFMISC_1:33;
then
(
x in {2,3} &
y in {0 ,1} )
by TARSKI:def 2;
then A62:
(
x in dom (2,3 --> c,d) &
y in dom (0 ,1 --> a,b) )
by FUNCT_4:65;
then A63:
f . y =
(0 ,1 --> a,b) . 1
by A35, A61, FUNCT_4:17
.=
b
by FUNCT_4:66
;
(0 ,1 --> a,b) +* (2,3 --> c,d) = (2,3 --> c,d) +* (0 ,1 --> a,b)
by A35, FUNCT_4:36;
then f . x =
(2,3 --> c,d) . 2
by A35, A61, A62, FUNCT_4:17
.=
c
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A63, ENUMSET1:def 4;
:: thesis: verum end; suppose
[x,y] = [2,3]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A64:
(
x = 2 &
y = 3 )
by ZFMISC_1:33;
then
(
x in {2,3} &
y in {2,3} )
by TARSKI:def 2;
then A65:
(
x in dom (2,3 --> c,d) &
y in dom (2,3 --> c,d) )
by FUNCT_4:65;
A66:
(0 ,1 --> a,b) +* (2,3 --> c,d) = (2,3 --> c,d) +* (0 ,1 --> a,b)
by A35, FUNCT_4:36;
then A67:
f . x =
(2,3 --> c,d) . 2
by A35, A64, A65, FUNCT_4:17
.=
c
by FUNCT_4:66
;
f . y =
(2,3 --> c,d) . 3
by A35, A64, A65, A66, FUNCT_4:17
.=
d
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A67, ENUMSET1:def 4;
:: thesis: verum end; suppose
[x,y] = [3,2]
;
:: thesis: [(f . x),(f . y)] in the InternalRel of (subrelstr Z)then A68:
(
x = 3 &
y = 2 )
by ZFMISC_1:33;
then
(
x in {3,2} &
y in {3,2} )
by TARSKI:def 2;
then A69:
(
x in dom (2,3 --> c,d) &
y in dom (2,3 --> c,d) )
by FUNCT_4:65;
A70:
(0 ,1 --> a,b) +* (2,3 --> c,d) = (2,3 --> c,d) +* (0 ,1 --> a,b)
by A35, FUNCT_4:36;
then A71:
f . x =
(2,3 --> c,d) . 3
by A35, A68, A69, FUNCT_4:17
.=
d
by FUNCT_4:66
;
f . y =
(2,3 --> c,d) . 2
by A35, A68, A69, A70, FUNCT_4:17
.=
c
by FUNCT_4:66
;
hence
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
by A9, A71, ENUMSET1:def 4;
:: thesis: verum end; end;
end;
thus
(
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z) implies
[x,y] in the
InternalRel of
(Necklace 4) )
:: thesis: verumproof
assume A72:
[(f . x),(f . y)] in the
InternalRel of
(subrelstr Z)
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)
A73:
(
dom (0 ,1 --> a,b) = {0 ,1} &
rng (0 ,1 --> a,b) = {a,b} )
by FUNCT_4:65, FUNCT_4:67;
then reconsider g =
0 ,1
--> a,
b as
Function of
{0 ,1},
{a,b} by FUNCT_2:def 1, RELSET_1:11;
reconsider G =
g " as
Function of
{a,b},
{0 ,1} by A32, A38, FUNCT_2:31;
A74:
(
dom (2,3 --> c,d) = {2,3} &
rng (2,3 --> c,d) = {c,d} )
by FUNCT_4:65, FUNCT_4:67;
then reconsider h = 2,3
--> c,
d as
Function of
{2,3},
{c,d} by FUNCT_2:def 1, RELSET_1:11;
reconsider Hh =
h " as
Function of
{c,d},
{2,3} by A33, A43, FUNCT_2:31;
reconsider F =
f " as
Function of the
carrier of
(subrelstr Z),the
carrier of
(Necklace 4) by A37, A50, FUNCT_2:31;
A75:
(
dom G = {a,b} &
rng G = {0 ,1} )
by A38, A73, FUNCT_1:55;
A76:
(
dom Hh = {c,d} &
rng Hh = {2,3} )
by A43, A74, FUNCT_1:55;
then
G +* Hh = Hh +* G
by A32, A33, A48, A75, FUNCT_4:36;
then A77:
(
F = G +* Hh &
F = Hh +* G )
by A35, A38, A43, A48, NECKLACE:8;
A78:
(
G = a,
b --> 0 ,1 &
Hh = c,
d --> 2,3 )
by A30, NECKLACE:11;
per cases
( [(f . x),(f . y)] = [a,b] or [(f . x),(f . y)] = [b,a] or [(f . x),(f . y)] = [b,c] or [(f . x),(f . y)] = [c,b] or [(f . x),(f . y)] = [c,d] or [(f . x),(f . y)] = [d,c] )
by A9, A72, ENUMSET1:def 4;
suppose
[(f . x),(f . y)] = [a,b]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A79:
(
f . x = a &
f . y = b )
by ZFMISC_1:33;
then A80:
(
f . x in {a,b} &
f . y in {a,b} )
by TARSKI:def 2;
A81:
(
f . x in dom G &
f . y in dom G )
by A75, A79, TARSKI:def 2;
F . (f . x) =
G . a
by A32, A33, A48, A75, A76, A77, A79, A80, FUNCT_4:17
.=
0
by A30, A78, FUNCT_4:66
;
then A82:
x = 0
by A34, A50, FUNCT_2:32;
A83:
F . (f . y) =
G . b
by A32, A33, A48, A75, A76, A77, A79, A81, FUNCT_4:17
.=
1
by A78, FUNCT_4:66
;
F . (f . y) = y
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A82, A83, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; suppose
[(f . x),(f . y)] = [b,a]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A84:
(
f . x = b &
f . y = a )
by ZFMISC_1:33;
then A85:
(
f . x in {a,b} &
f . y in {a,b} )
by TARSKI:def 2;
A86:
(
f . x in dom G &
f . y in dom G )
by A75, A84, TARSKI:def 2;
F . (f . y) =
G . a
by A32, A33, A48, A75, A76, A77, A84, A85, FUNCT_4:17
.=
0
by A30, A78, FUNCT_4:66
;
then A87:
y = 0
by A34, A50, FUNCT_2:32;
A88:
F . (f . x) =
G . b
by A32, A33, A48, A75, A76, A77, A84, A86, FUNCT_4:17
.=
1
by A78, FUNCT_4:66
;
F . (f . x) = x
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A87, A88, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; suppose
[(f . x),(f . y)] = [b,c]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A89:
(
f . x = b &
f . y = c )
by ZFMISC_1:33;
then A90:
(
f . x in dom G &
f . y in dom Hh )
by A75, A76, TARSKI:def 2;
then F . (f . x) =
G . b
by A32, A33, A48, A75, A76, A77, A89, FUNCT_4:17
.=
1
by A78, FUNCT_4:66
;
then A91:
x = 1
by A34, A50, FUNCT_2:32;
A92:
F . (f . y) =
Hh . c
by A32, A33, A48, A75, A76, A77, A89, A90, FUNCT_4:17
.=
2
by A30, A78, FUNCT_4:66
;
F . (f . y) = y
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A91, A92, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; suppose
[(f . x),(f . y)] = [c,b]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A93:
(
f . x = c &
f . y = b )
by ZFMISC_1:33;
then A94:
(
f . x in dom Hh &
f . y in dom G )
by A75, A76, TARSKI:def 2;
then F . (f . y) =
G . b
by A32, A33, A48, A75, A76, A77, A93, FUNCT_4:17
.=
1
by A78, FUNCT_4:66
;
then A95:
y = 1
by A34, A50, FUNCT_2:32;
A96:
F . (f . x) =
Hh . c
by A32, A33, A48, A75, A76, A77, A93, A94, FUNCT_4:17
.=
2
by A30, A78, FUNCT_4:66
;
F . (f . x) = x
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A95, A96, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; suppose
[(f . x),(f . y)] = [c,d]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A97:
(
f . x = c &
f . y = d )
by ZFMISC_1:33;
then A98:
(
f . x in {c,d} &
f . y in {c,d} )
by TARSKI:def 2;
A99:
(
f . x in dom Hh &
f . y in dom Hh )
by A76, A97, TARSKI:def 2;
F . (f . x) =
Hh . c
by A32, A33, A48, A75, A76, A77, A97, A98, FUNCT_4:17
.=
2
by A30, A78, FUNCT_4:66
;
then A100:
x = 2
by A34, A50, FUNCT_2:32;
A101:
F . (f . y) =
Hh . d
by A32, A33, A48, A75, A76, A77, A97, A99, FUNCT_4:17
.=
3
by A78, FUNCT_4:66
;
F . (f . y) = y
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A100, A101, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; suppose
[(f . x),(f . y)] = [d,c]
;
:: thesis: [x,y] in the InternalRel of (Necklace 4)then A102:
(
f . x = d &
f . y = c )
by ZFMISC_1:33;
then A103:
(
f . x in {c,d} &
f . y in {c,d} )
by TARSKI:def 2;
A104:
(
f . x in dom Hh &
f . y in dom Hh )
by A76, A102, TARSKI:def 2;
F . (f . y) =
Hh . c
by A32, A33, A48, A75, A76, A77, A102, A103, FUNCT_4:17
.=
2
by A30, A78, FUNCT_4:66
;
then A105:
y = 2
by A34, A50, FUNCT_2:32;
A106:
F . (f . x) =
Hh . d
by A32, A33, A48, A75, A76, A77, A102, A104, FUNCT_4:17
.=
3
by A78, FUNCT_4:66
;
F . (f . x) = x
by A34, A50, FUNCT_2:32;
hence
[x,y] in the
InternalRel of
(Necklace 4)
by A105, A106, ENUMSET1:def 4, NECKLA_2:2;
:: thesis: verum end; end;
end;
end;
hence
subrelstr Z embeds Necklace 4
by A50, NECKLACE:def 2; :: thesis: verum