Metamath Proof Explorer


Theorem breqtrri

Description: Substitution of equal classes into a binary relation. (Contributed by NM, 1-Aug-1999)

Ref Expression
Hypotheses breqtrr.1 ARB
breqtrr.2 C=B
Assertion breqtrri ARC

Proof

Step Hyp Ref Expression
1 breqtrr.1 ARB
2 breqtrr.2 C=B
3 2 eqcomi B=C
4 1 3 breqtri ARC