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Theorem ax6b 1541
Description: Quantified Negation. Axiom C5-2 of [Monk2] p. 113.

(Contributed by GD, 27-Jan-2018.)

Assertion
Ref Expression
ax6b (¬ ∀𝑥𝜑 → ∀𝑥 ¬ ∀𝑥𝜑)

Proof of Theorem ax6b
StepHypRef Expression
1 ax-ial 1427 . 2 (∀𝑥𝜑 → ∀𝑥𝑥𝜑)
21ax6blem 1540 1 (¬ ∀𝑥𝜑 → ∀𝑥 ¬ ∀𝑥𝜑)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wal 1241
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545  ax-5 1336  ax-gen 1338  ax-ie2 1383  ax-ial 1427
This theorem depends on definitions:  df-bi 110  df-tru 1246  df-fal 1249
This theorem is referenced by:  hbn1  1542  hbnt  1543
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