Metamath Proof Explorer


Theorem breqd

Description: Equality deduction for a binary relation. (Contributed by NM, 29-Oct-2011)

Ref Expression
Hypothesis breq1d.1
|- ( ph -> A = B )
Assertion breqd
|- ( ph -> ( C A D <-> C B D ) )

Proof

Step Hyp Ref Expression
1 breq1d.1
 |-  ( ph -> A = B )
2 breq
 |-  ( A = B -> ( C A D <-> C B D ) )
3 1 2 syl
 |-  ( ph -> ( C A D <-> C B D ) )