Metamath Proof Explorer


Theorem cbvopab1vOLD

Description: Obsolete version of cbvopab1v as of 17-Nov-2024. (Contributed by NM, 31-Jul-2003) (Proof shortened by Eric Schmidt, 4-Apr-2007) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis cbvopab1vOLD.1
|- ( x = z -> ( ph <-> ps ) )
Assertion cbvopab1vOLD
|- { <. x , y >. | ph } = { <. z , y >. | ps }

Proof

Step Hyp Ref Expression
1 cbvopab1vOLD.1
 |-  ( x = z -> ( ph <-> ps ) )
2 nfv
 |-  F/ z ph
3 nfv
 |-  F/ x ps
4 2 3 1 cbvopab1
 |-  { <. x , y >. | ph } = { <. z , y >. | ps }