Theorem nfe1OLD 2033

Description: Obsolete proof of nfe1 2027 as of 6-Oct-2021. (Contributed by Mario Carneiro, 11-Aug-2016.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
nfe1OLD	|- F/ x E. x ph

Proof of Theorem nfe1OLD

Step	Hyp	Ref	Expression
1		hbe1 2021	. 2 |- ( E. x ph -> A. x E. x ph )
2	1	nfiOLD 1734	1 |- F/ x E. x ph

Syntax hints:   E.wex 1704   F/wnfOLD 1709

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-10 2019

This theorem depends on definitions:  df-bi 197  df-ex 1705  df-nfOLD 1721

This theorem is referenced by: (None)