Theorem nexdOLD 2198

Description: Obsolete proof of nexd 2089 as of 6-Oct-2021. (Contributed by Mario Carneiro, 24-Sep-2016.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypotheses

Ref	Expression
nexdOLD.1	|- F/ x ph
nexdOLD.2	|- ( ph -> -. ps )

Assertion

Ref	Expression
nexdOLD	|- ( ph -> -. E. x ps )

Proof of Theorem nexdOLD

Step	Hyp	Ref	Expression
1		nexdOLD.1	. . 3 |- F/ x ph
2	1	nfriOLD 2189	. 2 |- ( ph -> A. x ph )
3		nexdOLD.2	. 2 |- ( ph -> -. ps )
4	2, 3	nexdh 1792	1 |- ( ph -> -. E. x ps )

Syntax hints:   -. wn 3   -> wi 4   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-5 1839  ax-6 1888  ax-7 1935  ax-12 2047

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

This theorem is referenced by: (None)