Theorem ax12inda2ALT 39445

Description: Alternate proof of ax12inda2 39446, slightly more direct and not requiring ax-c16 39391. (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 39397	. . . . . . 7 ⊢ (∀𝑥𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑))
3	2	a1i 11	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑥𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑)))
4		biidd 263	. . . . . . 7 ⊢ (∀𝑧 𝑧 = 𝑥 → (𝜑 ↔ 𝜑))
5	4	dral1-o 39403	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑧𝜑 ↔ ∀𝑥𝜑))
6	5	imbi2d 341	. . . . . . 7 ⊢ (∀𝑧 𝑧 = 𝑥 → ((𝑥 = 𝑦 → ∀𝑧𝜑) ↔ (𝑥 = 𝑦 → ∀𝑥𝜑)))
7	6	dral2-o 39429	. . . . . 6 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → ∀𝑥𝜑)))
8	3, 5, 7	3imtr4d 295	. . . . 5 ⊢ (∀𝑧 𝑧 = 𝑥 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
9	8	aecoms-o 39401	. . . 4 ⊢ (∀𝑥 𝑥 = 𝑧 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
10	9	a1d 25	. . 3 ⊢ (∀𝑥 𝑥 = 𝑧 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑))))
11	10	a1d 25	. 2 ⊢ (∀𝑥 𝑥 = 𝑧 → (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))))
12		simplr 774	. . . . 5 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → ¬ ∀𝑥 𝑥 = 𝑦)
13		dveeq1-o 39434	. . . . . . . 8 ⊢ (¬ ∀𝑧 𝑧 = 𝑥 → (𝑥 = 𝑦 → ∀𝑧 𝑥 = 𝑦))
14	13	naecoms-o 39426	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (𝑥 = 𝑦 → ∀𝑧 𝑥 = 𝑦))
15	14	imp 407	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑧 ∧ 𝑥 = 𝑦) → ∀𝑧 𝑥 = 𝑦)
16	15	adantlr 721	. . . . 5 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → ∀𝑧 𝑥 = 𝑦)
17		hbnae-o 39427	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑦)
18		hba1-o 39396	. . . . . . 7 ⊢ (∀𝑧 𝑥 = 𝑦 → ∀𝑧∀𝑧 𝑥 = 𝑦)
19	17, 18	hban 2311	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → ∀𝑧(¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦))
20		ax-c5 39382	. . . . . . 7 ⊢ (∀𝑧 𝑥 = 𝑦 → 𝑥 = 𝑦)
21		ax12inda2.1	. . . . . . . 8 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑))))
22	21	imp 407	. . . . . . 7 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ 𝑥 = 𝑦) → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑)))
23	20, 22	sylan2 599	. . . . . 6 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → (𝜑 → ∀𝑥(𝑥 = 𝑦 → 𝜑)))
24	19, 23	alimdh 1824	. . . . 5 ⊢ ((¬ ∀𝑥 𝑥 = 𝑦 ∧ ∀𝑧 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑)))
25	12, 16, 24	syl2anc 590	. . . 4 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑)))
26		ax-11 2168	. . . . . 6 ⊢ (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥∀𝑧(𝑥 = 𝑦 → 𝜑))
27		hbnae-o 39427	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → ∀𝑥 ¬ ∀𝑥 𝑥 = 𝑧)
28		hbnae-o 39427	. . . . . . . . 9 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → ∀𝑧 ¬ ∀𝑥 𝑥 = 𝑧)
29	28, 14	nf5dh 2158	. . . . . . . 8 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → Ⅎ𝑧 𝑥 = 𝑦)
30		19.21t 2218	. . . . . . . 8 ⊢ (Ⅎ𝑧 𝑥 = 𝑦 → (∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ (𝑥 = 𝑦 → ∀𝑧𝜑)))
31	29, 30	syl 17	. . . . . . 7 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ (𝑥 = 𝑦 → ∀𝑧𝜑)))
32	27, 31	albidh 1873	. . . . . 6 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑥∀𝑧(𝑥 = 𝑦 → 𝜑) ↔ ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
33	26, 32	imbitrid 245	. . . . 5 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
34	33	ad2antrr 732	. . . 4 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧∀𝑥(𝑥 = 𝑦 → 𝜑) → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
35	25, 34	syld 47	. . 3 ⊢ (((¬ ∀𝑥 𝑥 = 𝑧 ∧ ¬ ∀𝑥 𝑥 = 𝑦) ∧ 𝑥 = 𝑦) → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))
36	35	exp31 420	. 2 ⊢ (¬ ∀𝑥 𝑥 = 𝑧 → (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑)))))
37	11, 36	pm2.61i 183	1 ⊢ (¬ ∀𝑥 𝑥 = 𝑦 → (𝑥 = 𝑦 → (∀𝑧𝜑 → ∀𝑥(𝑥 = 𝑦 → ∀𝑧𝜑))))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 207   ∧ wa 396  ∀wal 1545  Ⅎwnf 1790

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-10 2152  ax-11 2168  ax-12 2189  ax-13 2380  ax-c5 39382  ax-c4 39383  ax-c7 39384  ax-c10 39385  ax-c11 39386  ax-c9 39389

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-tru 1550  df-ex 1787  df-nf 1791

This theorem is referenced by: (None)