Theorem dvelimh 2443

Description: Version of dvelim 2444 without any variable restrictions. Usage of this theorem is discouraged because it depends on ax-13 2365. Check out dvelimhw 2335 for a version requiring fewer axioms. (Contributed by NM, 1-Oct-2002.) (Proof shortened by Wolf Lammen, 11-May-2018.) (New usage is discouraged.)

Hypotheses

Ref	Expression
dvelimh.1	⊢ (𝜑 → ∀𝑥𝜑)
dvelimh.2	⊢ (𝜓 → ∀𝑧𝜓)
dvelimh.3	⊢ (𝑧 = 𝑦 → (𝜑 ↔ 𝜓))

Assertion

Ref	Expression
dvelimh	⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝜓 → ∀𝑥𝜓))

Proof of Theorem dvelimh

Step	Hyp	Ref	Expression
1		dvelimh.1	. . . 4 ⊢ (𝜑 → ∀𝑥𝜑)
2	1	nf5i 2134	. . 3 ⊢ Ⅎ𝑥𝜑
3		dvelimh.2	. . . 4 ⊢ (𝜓 → ∀𝑧𝜓)
4	3	nf5i 2134	. . 3 ⊢ Ⅎ𝑧𝜓
5		dvelimh.3	. . 3 ⊢ (𝑧 = 𝑦 → (𝜑 ↔ 𝜓))
6	2, 4, 5	dvelimf 2441	. 2 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥𝜓)
7	6	nf5rd 2181	1 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝜓 → ∀𝑥𝜓))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205  ∀wal 1531

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-10 2129  ax-11 2146  ax-12 2163  ax-13 2365

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-tru 1536  df-ex 1774  df-nf 1778

This theorem is referenced by:  dvelim  2444  dveeq1-o16  38317  dveel2ALT  38320  ax6e2nd  43876  ax6e2ndVD  44226  ax6e2ndALT  44248