let A be partial non-empty UAStr ; for R being Equivalence_Relation of the carrier of A st R c= DomRel A holds
( R |^ A is total & R |^ A is symmetric & R |^ A is transitive )
let R be Equivalence_Relation of the carrier of A; ( R c= DomRel A implies ( R |^ A is total & R |^ A is symmetric & R |^ A is transitive ) )
assume A1:
R c= DomRel A
; ( R |^ A is total & R |^ A is symmetric & R |^ A is transitive )
then A4:
R |^ A is_reflexive_in the carrier of A
;
then A5:
dom (R |^ A) = the carrier of A
by ORDERS_1:13;
A6:
field (R |^ A) = the carrier of A
by A4, ORDERS_1:13;
thus
R |^ A is total
by A5, PARTFUN1:def 2; ( R |^ A is symmetric & R |^ A is transitive )
now for x, y being object st x in the carrier of A & y in the carrier of A & [x,y] in R |^ A holds
[y,x] in R |^ Alet x,
y be
object ;
( x in the carrier of A & y in the carrier of A & [x,y] in R |^ A implies [y,x] in R |^ A )assume that A7:
x in the
carrier of
A
and A8:
y in the
carrier of
A
;
( [x,y] in R |^ A implies [y,x] in R |^ A )reconsider a =
x,
b =
y as
Element of
A by A7, A8;
assume A9:
[x,y] in R |^ A
;
[y,x] in R |^ Athen A10:
[a,b] in R
by Def5;
now ( [b,a] in R & ( for f being operation of A
for p, q being FinSequence st (p ^ <*b*>) ^ q in dom f & (p ^ <*a*>) ^ q in dom f holds
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in R ) )thus
[b,a] in R
by A10, EQREL_1:6;
for f being operation of A
for p, q being FinSequence st (p ^ <*b*>) ^ q in dom f & (p ^ <*a*>) ^ q in dom f holds
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in Rlet f be
operation of
A;
for p, q being FinSequence st (p ^ <*b*>) ^ q in dom f & (p ^ <*a*>) ^ q in dom f holds
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in Rlet p,
q be
FinSequence;
( (p ^ <*b*>) ^ q in dom f & (p ^ <*a*>) ^ q in dom f implies [(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in R )assume that A11:
(p ^ <*b*>) ^ q in dom f
and A12:
(p ^ <*a*>) ^ q in dom f
;
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in R
[(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*b*>) ^ q))] in R
by A9, A11, A12, Def5;
hence
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*a*>) ^ q))] in R
by EQREL_1:6;
verum end; hence
[y,x] in R |^ A
by Def5;
verum end;
then
R |^ A is_symmetric_in the carrier of A
;
hence
R |^ A is symmetric
by A6; R |^ A is transitive
now for x, y, z being object st x in the carrier of A & y in the carrier of A & z in the carrier of A & [x,y] in R |^ A & [y,z] in R |^ A holds
[x,z] in R |^ Alet x,
y,
z be
object ;
( x in the carrier of A & y in the carrier of A & z in the carrier of A & [x,y] in R |^ A & [y,z] in R |^ A implies [x,z] in R |^ A )assume that A13:
x in the
carrier of
A
and A14:
y in the
carrier of
A
and A15:
z in the
carrier of
A
;
( [x,y] in R |^ A & [y,z] in R |^ A implies [x,z] in R |^ A )reconsider a =
x,
b =
y,
c =
z as
Element of
A by A13, A14, A15;
assume that A16:
[x,y] in R |^ A
and A17:
[y,z] in R |^ A
;
[x,z] in R |^ AA18:
now for f being operation of A
for p, q being FinSequence st (p ^ <*a*>) ^ q in dom f & (p ^ <*c*>) ^ q in dom f holds
[(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*c*>) ^ q))] in Rlet f be
operation of
A;
for p, q being FinSequence st (p ^ <*a*>) ^ q in dom f & (p ^ <*c*>) ^ q in dom f holds
[(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*c*>) ^ q))] in Rlet p,
q be
FinSequence;
( (p ^ <*a*>) ^ q in dom f & (p ^ <*c*>) ^ q in dom f implies [(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*c*>) ^ q))] in R )A19:
[a,b] in R
by A16, Def5;
A20:
(
(p ^ <*a*>) ^ q in dom f &
(p ^ <*b*>) ^ q in dom f implies
[(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*b*>) ^ q))] in R )
by A16, Def5;
(
(p ^ <*b*>) ^ q in dom f &
(p ^ <*c*>) ^ q in dom f implies
[(f . ((p ^ <*b*>) ^ q)),(f . ((p ^ <*c*>) ^ q))] in R )
by A17, Def5;
hence
(
(p ^ <*a*>) ^ q in dom f &
(p ^ <*c*>) ^ q in dom f implies
[(f . ((p ^ <*a*>) ^ q)),(f . ((p ^ <*c*>) ^ q))] in R )
by A1, A19, A20, Def4, EQREL_1:7;
verum end; A21:
[a,b] in R
by A16, Def5;
[b,c] in R
by A17, Def5;
then
[a,c] in R
by A21, EQREL_1:7;
hence
[x,z] in R |^ A
by A18, Def5;
verum end;
then
R |^ A is_transitive_in the carrier of A
;
hence
R |^ A is transitive
by A6; verum