Theorem bj-nnfea 34083

Description: Nonfreeness implies the equivalent of ax5ea 1913. (Contributed by BJ, 28-Jul-2023.)

Assertion

Ref	Expression
bj-nnfea	⊢ (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → ∀𝑥𝜑))

Proof of Theorem bj-nnfea

Step	Hyp	Ref	Expression
1		bj-nnfe 34081	. 2 ⊢ (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → 𝜑))
2		bj-nnfa 34079	. 2 ⊢ (Ⅎ'𝑥𝜑 → (𝜑 → ∀𝑥𝜑))
3	1, 2	syld 47	1 ⊢ (Ⅎ'𝑥𝜑 → (∃𝑥𝜑 → ∀𝑥𝜑))

Syntax hints:   → wi 4  ∀wal 1534  ∃wex 1779  Ⅎ'wnnf 34074

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 209  df-an 399  df-bj-nnf 34075

This theorem is referenced by:  bj-nnfead  34084  bj-nnfnfTEMP  34086  bj-dfnnf3  34105