Theorem hbnae 2462

Description: All variables are effectively bound in a distinct variable specifier. Lemma L19 in [Megill] p. 446 (p. 14 of the preprint). Usage of this theorem is discouraged because it depends on ax-13 2402. Use the weaker hbnaev 2092 when possible. (Contributed by NM, 13-May-1993.) (New usage is discouraged.)

Assertion

Ref	Expression
hbnae	⊢ (¬ ∀𝑥 𝑥 = 𝑦 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑦)

Proof of Theorem hbnae

Step	Hyp	Ref	Expression
1		hbae 2461	. 2 ⊢ (∀𝑥 𝑥 = 𝑦 → ∀𝑧∀𝑥 𝑥 = 𝑦)
2	1	hbn 2328	1 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑦)

Syntax hints:  ¬ wn 3   → wi 4  ∀wal 1566

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-10 2174  ax-11 2190  ax-12 2211  ax-13 2402

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-tru 1571  df-ex 1808  df-nf 1812

This theorem is referenced by:  hbnaes  2465  eujustALT  2598  bj-hbnaeb  37399  ax6e2nd  45215  ax6e2ndVD  45564  ax6e2ndeqVD  45565  ax6e2ndALT  45586  ax6e2ndeqALT  45587