let f1, f2 be Function of L,(EqRelLATT A); :: thesis: ( ( for e being Element of L ex E being Equivalence_Relation of A st
( E = f1 . e & ( for x, y being Element of A holds
( [x,y] in E iff d . x,y <= e ) ) ) ) & ( for e being Element of L ex E being Equivalence_Relation of A st
( E = f2 . e & ( for x, y being Element of A holds
( [x,y] in E iff d . x,y <= e ) ) ) ) implies f1 = f2 )
assume that
A12:
for e being Element of L ex E being Equivalence_Relation of A st
( E = f1 . e & ( for x, y being Element of A holds
( [x,y] in E iff d . x,y <= e ) ) )
and
A13:
for e being Element of L ex E being Equivalence_Relation of A st
( E = f2 . e & ( for x, y being Element of A holds
( [x,y] in E iff d . x,y <= e ) ) )
; :: thesis: f1 = f2
A14:
for e being Element of L holds f1 . e = f2 . e
proof
let e be
Element of
L;
:: thesis: f1 . e = f2 . e
consider E1 being
Equivalence_Relation of
A such that A15:
(
E1 = f1 . e & ( for
x,
y being
Element of
A holds
(
[x,y] in E1 iff
d . x,
y <= e ) ) )
by A12;
consider E2 being
Equivalence_Relation of
A such that A16:
(
E2 = f2 . e & ( for
x,
y being
Element of
A holds
(
[x,y] in E2 iff
d . x,
y <= e ) ) )
by A13;
A17:
for
x,
y being
Element of
A holds
(
[x,y] in E1 iff
[x,y] in E2 )
for
x,
y being
set holds
(
[x,y] in E1 iff
[x,y] in E2 )
proof
let x,
y be
set ;
:: thesis: ( [x,y] in E1 iff [x,y] in E2 )
A18:
(
field E1 = A &
field E2 = A )
by EQREL_1:16;
assume A20:
[x,y] in E2
;
:: thesis: [x,y] in E1
then reconsider x' =
x,
y' =
y as
Element of
A by A18, RELAT_1:30;
[x',y'] in E1
by A17, A20;
hence
[x,y] in E1
;
:: thesis: verum
end;
hence
f1 . e = f2 . e
by A15, A16, RELAT_1:def 2;
:: thesis: verum
end;
reconsider f1' = f1, f2' = f2 as Function of the carrier of L,the carrier of (EqRelLATT A) ;
for e being set st e in the carrier of L holds
f1' . e = f2' . e
by A14;
hence
f1 = f2
by FUNCT_2:18; :: thesis: verum