Metamath Proof Explorer


Theorem vtoclgOLDOLD

Description: Obsolete version of vtoclg as of 20-Apr-2024. (Contributed by NM, 17-Apr-1995) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses vtoclg.1
|- ( x = A -> ( ph <-> ps ) )
vtoclg.2
|- ph
Assertion vtoclgOLDOLD
|- ( A e. V -> ps )

Proof

Step Hyp Ref Expression
1 vtoclg.1
 |-  ( x = A -> ( ph <-> ps ) )
2 vtoclg.2
 |-  ph
3 nfv
 |-  F/ x ps
4 3 1 2 vtoclg1f
 |-  ( A e. V -> ps )