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Theorem nfe1OLD 2073
Description: Obsolete proof of nfe1 2067 as of 6-Oct-2021. (Contributed by Mario Carneiro, 11-Aug-2016.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
nfe1OLD 𝑥𝑥𝜑

Proof of Theorem nfe1OLD
StepHypRef Expression
1 hbe1 2061 . 2 (∃𝑥𝜑 → ∀𝑥𝑥𝜑)
21nfiOLD 1774 1 𝑥𝑥𝜑
Colors of variables: wff setvar class
Syntax hints:  wex 1744  wnfOLD 1749
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1762  ax-4 1777  ax-10 2059
This theorem depends on definitions:  df-bi 197  df-ex 1745  df-nfOLD 1761
This theorem is referenced by: (None)
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