let R1, R2 be Relation of (Bags I); ( ( for b1, b2 being bag of I holds
( [b1,b2] in R1 iff ( b1 <> b2 & b1 divides b2 ) ) ) & ( for b1, b2 being bag of I holds
( [b1,b2] in R2 iff ( b1 <> b2 & b1 divides b2 ) ) ) implies R1 = R2 )
assume that
A1:
for b1, b2 being bag of I holds
( [b1,b2] in R1 iff ( b1 <> b2 & b1 divides b2 ) )
and
A2:
for b1, b2 being bag of I holds
( [b1,b2] in R2 iff ( b1 <> b2 & b1 divides b2 ) )
; R1 = R2
let b1, b2 be Element of Bags I; RELSET_1:def 2 ( ( not [b1,b2] in R1 or [b1,b2] in R2 ) & ( not [b1,b2] in R2 or [b1,b2] in R1 ) )
( [b1,b2] in R1 iff ( b1 <> b2 & b1 divides b2 ) )
by A1;
hence
( ( not [b1,b2] in R1 or [b1,b2] in R2 ) & ( not [b1,b2] in R2 or [b1,b2] in R1 ) )
by A2; verum