Metamath Proof Explorer


Theorem eqbrtri

Description: Substitution of equal classes into a binary relation. (Contributed by NM, 1-Aug-1999)

Ref Expression
Hypotheses eqbrtr.1 A = B
eqbrtr.2 B R C
Assertion eqbrtri A R C

Proof

Step Hyp Ref Expression
1 eqbrtr.1 A = B
2 eqbrtr.2 B R C
3 1 breq1i A R C B R C
4 2 3 mpbir A R C