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Theorem bj-nnfea 34916
Description: Nonfreeness implies the equivalent of ax5ea 1916. (Contributed by BJ, 28-Jul-2023.)
Assertion
Ref Expression
bj-nnfea (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → ∀𝑥𝜑))

Proof of Theorem bj-nnfea
StepHypRef Expression
1 bj-nnfe 34913 . 2 (Ⅎ'𝑥𝜑 → (∃𝑥𝜑𝜑))
2 bj-nnfa 34910 . 2 (Ⅎ'𝑥𝜑 → (𝜑 → ∀𝑥𝜑))
31, 2syld 47 1 (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → ∀𝑥𝜑))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wal 1537  wex 1782  Ⅎ'wnnf 34905
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 206  df-an 397  df-bj-nnf 34906
This theorem is referenced by:  bj-nnfead  34917  bj-nnfeai  34918  bj-nnfnfTEMP  34920  bj-dfnnf3  34939
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