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 φA=B
eqbrtrrd.2 φARC
Assertion eqbrtrrd φBRC

Proof

Step Hyp Ref Expression
1 eqbrtrrd.1 φA=B
2 eqbrtrrd.2 φARC
3 1 eqcomd φB=A
4 3 2 eqbrtrd φBRC