Metamath Proof Explorer


Theorem trpredeq3d

Description: Equality deduction for transitive predecessors. (Contributed by Scott Fenton, 2-Feb-2011)

Ref Expression
Hypothesis trpredeq3d.1
|- ( ph -> X = Y )
Assertion trpredeq3d
|- ( ph -> TrPred ( R , A , X ) = TrPred ( R , A , Y ) )

Proof

Step Hyp Ref Expression
1 trpredeq3d.1
 |-  ( ph -> X = Y )
2 trpredeq3
 |-  ( X = Y -> TrPred ( R , A , X ) = TrPred ( R , A , Y ) )
3 1 2 syl
 |-  ( ph -> TrPred ( R , A , X ) = TrPred ( R , A , Y ) )