Theorem axprglem 5394

Description: Lemma for axprg 5395. (Contributed by GG, 11-Mar-2026.)

Assertion

Ref	Expression
axprglem	⊢ (𝑥 = 𝐴 → ∃𝑧∀𝑤((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))

Distinct variable groups:   𝑥,𝐴,𝑧,𝑤   𝑥,𝐵,𝑧,𝑤

Proof of Theorem axprglem

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		iseqsetv-clel 2840	. . . 4 ⊢ (∃𝑦 𝑦 = 𝐵 ↔ ∃𝑤 𝑤 = 𝐵)
2		ax-pr 5391	. . . . . 6 ⊢ ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑦) → 𝑤 ∈ 𝑧)
3		eqtr3 2783	. . . . . . . . . . 11 ⊢ ((𝑤 = 𝐵 ∧ 𝑦 = 𝐵) → 𝑤 = 𝑦)
4	3	expcom 419	. . . . . . . . . 10 ⊢ (𝑦 = 𝐵 → (𝑤 = 𝐵 → 𝑤 = 𝑦))
5	4	orim2d 982	. . . . . . . . 9 ⊢ (𝑦 = 𝐵 → ((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → (𝑤 = 𝑥 ∨ 𝑤 = 𝑦)))
6	5	imim1d 83	. . . . . . . 8 ⊢ (𝑦 = 𝐵 → (((𝑤 = 𝑥 ∨ 𝑤 = 𝑦) → 𝑤 ∈ 𝑧) → ((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
7	6	alimdv 1949	. . . . . . 7 ⊢ (𝑦 = 𝐵 → (∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑦) → 𝑤 ∈ 𝑧) → ∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
8	7	eximdv 1950	. . . . . 6 ⊢ (𝑦 = 𝐵 → (∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑦) → 𝑤 ∈ 𝑧) → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
9	2, 8	mpi 21	. . . . 5 ⊢ (𝑦 = 𝐵 → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))
10	9	exlimiv 1963	. . . 4 ⊢ (∃𝑦 𝑦 = 𝐵 → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))
11	1, 10	sylbir 238	. . 3 ⊢ (∃𝑤 𝑤 = 𝐵 → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))
12		ax-pr 5391	. . . 4 ⊢ ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧)
13		alnex 1814	. . . . . 6 ⊢ (∀𝑤 ¬ 𝑤 = 𝐵 ↔ ¬ ∃𝑤 𝑤 = 𝐵)
14		orel2 904	. . . . . . . 8 ⊢ (¬ 𝑤 = 𝐵 → ((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 = 𝑥))
15		pm2.67-2 905	. . . . . . . 8 ⊢ (((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧) → (𝑤 = 𝑥 → 𝑤 ∈ 𝑧))
16	14, 15	syl9 78	. . . . . . 7 ⊢ (¬ 𝑤 = 𝐵 → (((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧) → ((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
17	16	al2imi 1848	. . . . . 6 ⊢ (∀𝑤 ¬ 𝑤 = 𝐵 → (∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧) → ∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
18	13, 17	sylbir 238	. . . . 5 ⊢ (¬ ∃𝑤 𝑤 = 𝐵 → (∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧) → ∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
19	18	eximdv 1950	. . . 4 ⊢ (¬ ∃𝑤 𝑤 = 𝐵 → (∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝑥) → 𝑤 ∈ 𝑧) → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
20	12, 19	mpi 21	. . 3 ⊢ (¬ ∃𝑤 𝑤 = 𝐵 → ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))
21	11, 20	pm2.61i 184	. 2 ⊢ ∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)
22		eqtr3 2783	. . . . . . 7 ⊢ ((𝑤 = 𝐴 ∧ 𝑥 = 𝐴) → 𝑤 = 𝑥)
23	22	expcom 419	. . . . . 6 ⊢ (𝑥 = 𝐴 → (𝑤 = 𝐴 → 𝑤 = 𝑥))
24	23	orim1d 981	. . . . 5 ⊢ (𝑥 = 𝐴 → ((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → (𝑤 = 𝑥 ∨ 𝑤 = 𝐵)))
25	24	imim1d 83	. . . 4 ⊢ (𝑥 = 𝐴 → (((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧) → ((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
26	25	alimdv 1949	. . 3 ⊢ (𝑥 = 𝐴 → (∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧) → ∀𝑤((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
27	26	eximdv 1950	. 2 ⊢ (𝑥 = 𝐴 → (∃𝑧∀𝑤((𝑤 = 𝑥 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧) → ∃𝑧∀𝑤((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧)))
28	21, 27	mpi 21	1 ⊢ (𝑥 = 𝐴 → ∃𝑧∀𝑤((𝑤 = 𝐴 ∨ 𝑤 = 𝐵) → 𝑤 ∈ 𝑧))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ∨ wo 861  ∀wal 1568   = wceq 1570  ∃wex 1812

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-8 2147  ax-9 2155  ax-ext 2733  ax-pr 5391

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2740  df-cleq 2753  df-clel 2836

This theorem is used by:  axprg  5395