Metamath Proof Explorer


Theorem eqbrtrrd

Description: Substitution of equal classes into a binary relation. (Contributed by NM, 24-Oct-1999)

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

Proof

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