Metamath Proof Explorer


Theorem breqtrrdi

Description: A chained equality inference for a binary relation. (Contributed by NM, 24-Apr-2005)

Ref Expression
Hypotheses breqtrrdi.1 φ A R B
breqtrrdi.2 C = B
Assertion breqtrrdi φ A R C

Proof

Step Hyp Ref Expression
1 breqtrrdi.1 φ A R B
2 breqtrrdi.2 C = B
3 2 eqcomi B = C
4 1 3 breqtrdi φ A R C