Metamath Proof Explorer


Theorem ceqsalvOLD

Description: Obsolete version of ceqsalv as of 8-Sep-2024. (Contributed by NM, 18-Aug-1993) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses ceqsalv.1
|- A e. _V
ceqsalv.2
|- ( x = A -> ( ph <-> ps ) )
Assertion ceqsalvOLD
|- ( A. x ( x = A -> ph ) <-> ps )

Proof

Step Hyp Ref Expression
1 ceqsalv.1
 |-  A e. _V
2 ceqsalv.2
 |-  ( x = A -> ( ph <-> ps ) )
3 nfv
 |-  F/ x ps
4 3 1 2 ceqsal
 |-  ( A. x ( x = A -> ph ) <-> ps )