Theorem dvelimdc 2979

Description: Deduction form of dvelimc 2980. Usage of this theorem is discouraged because it depends on ax-13 2379. (Contributed by Mario Carneiro, 8-Oct-2016.) (New usage is discouraged.)

Hypotheses

Ref	Expression
dvelimdc.1	⊢ Ⅎ𝑥𝜑
dvelimdc.2	⊢ Ⅎ𝑧𝜑
dvelimdc.3	⊢ (𝜑 → Ⅎ𝑥𝐴)
dvelimdc.4	⊢ (𝜑 → Ⅎ𝑧𝐵)
dvelimdc.5	⊢ (𝜑 → (𝑧 = 𝑦 → 𝐴 = 𝐵))

Assertion

Ref	Expression
dvelimdc	⊢ (𝜑 → (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥𝐵))

Proof of Theorem dvelimdc

Dummy variable 𝑤 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		nfv 1915	. . 3 ⊢ Ⅎ𝑤(𝜑 ∧ ¬ ∀𝑥 𝑥 = 𝑦)
2		dvelimdc.1	. . . . 5 ⊢ Ⅎ𝑥𝜑
3		dvelimdc.2	. . . . 5 ⊢ Ⅎ𝑧𝜑
4		dvelimdc.3	. . . . . 6 ⊢ (𝜑 → Ⅎ𝑥𝐴)
5	4	nfcrd 2945	. . . . 5 ⊢ (𝜑 → Ⅎ𝑥 𝑤 ∈ 𝐴)
6		dvelimdc.4	. . . . . 6 ⊢ (𝜑 → Ⅎ𝑧𝐵)
7	6	nfcrd 2945	. . . . 5 ⊢ (𝜑 → Ⅎ𝑧 𝑤 ∈ 𝐵)
8		dvelimdc.5	. . . . . 6 ⊢ (𝜑 → (𝑧 = 𝑦 → 𝐴 = 𝐵))
9		eleq2 2878	. . . . . 6 ⊢ (𝐴 = 𝐵 → (𝑤 ∈ 𝐴 ↔ 𝑤 ∈ 𝐵))
10	8, 9	syl6 35	. . . . 5 ⊢ (𝜑 → (𝑧 = 𝑦 → (𝑤 ∈ 𝐴 ↔ 𝑤 ∈ 𝐵)))
11	2, 3, 5, 7, 10	dvelimdf 2460	. . . 4 ⊢ (𝜑 → (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥 𝑤 ∈ 𝐵))
12	11	imp 410	. . 3 ⊢ ((𝜑 ∧ ¬ ∀𝑥 𝑥 = 𝑦) → Ⅎ𝑥 𝑤 ∈ 𝐵)
13	1, 12	nfcd 2944	. 2 ⊢ ((𝜑 ∧ ¬ ∀𝑥 𝑥 = 𝑦) → Ⅎ𝑥𝐵)
14	13	ex 416	1 ⊢ (𝜑 → (¬ ∀𝑥 𝑥 = 𝑦 → Ⅎ𝑥𝐵))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 399  ∀wal 1536   = wceq 1538  Ⅎwnf 1785   ∈ wcel 2111  Ⅎwnfc 2936

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-9 2121  ax-10 2142  ax-11 2158  ax-12 2175  ax-13 2379  ax-ext 2770

This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-tru 1541  df-ex 1782  df-nf 1786  df-cleq 2791  df-clel 2870  df-nfc 2938

This theorem is referenced by:  dvelimc  2980