Metamath Proof Explorer


Theorem vtocldOLD

Description: Obsolete version of vtocld as of 2-Sep-2024. (Contributed by Mario Carneiro, 15-Oct-2016) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses vtocld.1
|- ( ph -> A e. V )
vtocld.2
|- ( ( ph /\ x = A ) -> ( ps <-> ch ) )
vtocld.3
|- ( ph -> ps )
Assertion vtocldOLD
|- ( ph -> ch )

Proof

Step Hyp Ref Expression
1 vtocld.1
 |-  ( ph -> A e. V )
2 vtocld.2
 |-  ( ( ph /\ x = A ) -> ( ps <-> ch ) )
3 vtocld.3
 |-  ( ph -> ps )
4 nfv
 |-  F/ x ph
5 nfcvd
 |-  ( ph -> F/_ x A )
6 nfvd
 |-  ( ph -> F/ x ch )
7 1 2 3 4 5 6 vtocldf
 |-  ( ph -> ch )