Metamath Proof Explorer


Theorem eqbrtrrdi

Description: A chained equality inference for a binary relation. (Contributed by NM, 4-Jan-2006)

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

Proof

Step Hyp Ref Expression
1 eqbrtrrdi.1 φ B = A
2 eqbrtrrdi.2 B R C
3 1 eqcomd φ A = B
4 3 2 eqbrtrdi φ A R C