Theorem ax12inda2ALT 39971

Description: Alternate proof of ax12inda2 39972, slightly more direct and not requiring ax-c16 39917. (Contributed by NM, 4-May-2007.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypothesis

Ref	Expression
ax12inda2.1	⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑))))

Assertion

Ref	Expression
ax12inda2ALT	⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑))))

Distinct variable group:   𝑦,𝑧

Allowed substitution hints:   𝜑(𝑥, 𝑦, 𝑧)

Proof of Theorem ax12inda2ALT

Step	Hyp	Ref	Expression
1		ax-1 6	. . . . . . . 8 ⊢ (∀𝑥𝜑 → (𝑥 = 𝑦 → ∀𝑥𝜑))
2	1	axc4i-o 39923	. . . . . . 7 ⊢ (∀𝑥𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑))
3	2	a1i 11	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑥𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑)))
4		biidd 265	. . . . . . 7 ⊢ (∀𝑧 𝑧 = 𝑥 → (𝜑 ↔ 𝜑))
5	4	dral1-o 39929	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑧𝜑 ↔ ∀𝑥𝜑))
6	5	imbi2d 343	. . . . . . 7 ⊢ (∀𝑧 𝑧 = 𝑥 → ((𝑥 = 𝑦 → ∀𝑧𝜑) ↔ (𝑥 = 𝑦 → ∀𝑥𝜑)))
7	6	dral2-o 39955	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑)))
8	3, 5, 7	3imtr4d 297	. . . . 5 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
9	8	aecoms-o 39927	. . . 4 ⊢ (∀𝑥 𝑥 = 𝑧 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
10	9	a1d 26	. . 3 ⊢ (∀𝑥 𝑥 = 𝑧 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑))))
11	10	a1d 26	. 2 ⊢ (∀𝑥 𝑥 = 𝑧 → (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))))
12		simplr 781	. . . . 5 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → ¬ ∀𝑥 𝑥 = 𝑦)
13		dveeq1-o 39960	. . . . . . . 8 ⊢ (¬ ∀𝑧 𝑧 = 𝑥 → (𝑥 = 𝑦 → ∀𝑧 𝑥 = 𝑦))
14	13	naecoms-o 39952	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (𝑥 = 𝑦 → ∀𝑧 𝑥 = 𝑦))
15	14	imp 412	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑧 ∧ 𝑥 = 𝑦) → ∀𝑧 𝑥 = 𝑦)
16	15	adantlr 728	. . . . 5 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → ∀𝑧 𝑥 = 𝑦)
17		hbnae-o 39953	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑦)
18		hba1-o 39922	. . . . . . 7 ⊢ (∀𝑧 𝑥 = 𝑦 → ∀𝑧∀𝑧 𝑥 = 𝑦)
19	17, 18	hban 2334	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → ∀𝑧(¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦))
20		ax-c5 39908	. . . . . . 7 ⊢ (∀𝑧 𝑥 = 𝑦 → 𝑥 = 𝑦)
21		ax12inda2.1	. . . . . . . 8 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑))))
22	21	imp 412	. . . . . . 7 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ 𝑥 = 𝑦) → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑)))
23	20, 22	sylan2 605	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑)))
24	19, 23	alimdh 1850	. . . . 5 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑)))
25	12, 16, 24	syl2anc 596	. . . 4 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑)))
26		ax-11 2194	. . . . . 6 ⊢ (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥∀𝑧(𝑥 = 𝑦 → 𝜑))
27		hbnae-o 39953	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → ∀𝑥 ¬ ∀𝑥 𝑥 = 𝑧)
28		hbnae-o 39953	. . . . . . . . 9 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑧)
29	28, 14	nf5dh 2184	. . . . . . . 8 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → Ⅎ𝑧 𝑥 = 𝑦)
30		19.21t 2243	. . . . . . . 8 ⊢ (Ⅎ𝑧 𝑥 = 𝑦 → (∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ (𝑥 = 𝑦 → ∀𝑧𝜑)))
31	29, 30	syl 18	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ (𝑥 = 𝑦 → ∀𝑧𝜑)))
32	27, 31	albidh 1899	. . . . . 6 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑥∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
33	26, 32	imbitrid 247	. . . . 5 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
34	33	ad2antrr 739	. . . 4 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
35	25, 34	syld 48	. . 3 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
36	35	exp31 425	. 2 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))))
37	11, 36	pm2.61i 184	1 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑))))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1568  Ⅎwnf 1816

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-10 2178  ax-11 2194  ax-12 2213  ax-13 2402  ax-c5 39908  ax-c4 39909  ax-c7 39910  ax-c10 39911  ax-c11 39912  ax-c9 39915

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1573  df-ex 1813  df-nf 1817

This theorem is used by: (None)