let R1, R2 be Relation of D; ( ( for A, B being set holds
( [A,B] in R1 iff ( A in D & B in D & ( for a, b being set st a in A & b in B holds
[a,b] in the ToleranceRel of P ) ) ) ) & ( for A, B being set holds
( [A,B] in R2 iff ( A in D & B in D & ( for a, b being set st a in A & b in B holds
[a,b] in the ToleranceRel of P ) ) ) ) implies R1 = R2 )
assume that
A2:
for A, B being set holds
( [A,B] in R1 iff ( A in D & B in D & ( for a, b being set st a in A & b in B holds
[a,b] in the ToleranceRel of P ) ) )
and
A3:
for A, B being set holds
( [A,B] in R2 iff ( A in D & B in D & ( for a, b being set st a in A & b in B holds
[a,b] in the ToleranceRel of P ) ) )
; R1 = R2
let x, y be object ; RELAT_1:def 2 ( ( not [^,^] in R1 or [^,^] in R2 ) & ( not [^,^] in R2 or [^,^] in R1 ) )
reconsider a = x, b = y as set by TARSKI:1;
A4:
( [a,b] in R1 iff S1[a,b] )
by A2;
( [a,b] in R2 iff S1[a,b] )
by A3;
hence
( [x,y] in R1 iff [x,y] in R2 )
by A4; verum