Metamath Proof Explorer


Theorem eqbrtrd

Description: Substitution of equal classes into a binary relation. (Contributed by NM, 8-Oct-1999)

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

Proof

Step Hyp Ref Expression
1 eqbrtrd.1 φ A = B
2 eqbrtrd.2 φ B R C
3 1 breq1d φ A R C B R C
4 2 3 mpbird φ A R C