Theorem bj-elgab 37852

Description: Elements of a generalized class abstraction. (Contributed by BJ, 4-Oct-2024.)

Hypotheses

Ref	Expression
bj-elgab.nf	⊢ (𝜑 → ∀𝑥𝜑)
bj-elgab.nfa	⊢ (𝜑 → Ⅎ𝑥𝐴)
bj-elgab.ex	⊢ (𝜑 → 𝐴 ∈ 𝑉)
bj-elgab.is	⊢ (𝜑 → (∃𝑥(𝐴 = 𝐵 ∧ 𝜓) ↔ 𝜒))

Assertion

Ref	Expression
bj-elgab	⊢ (𝜑 → (𝐴 ∈ {𝐵 ∣ 𝑥 ∣ 𝜓} ↔ 𝜒))

Proof of Theorem bj-elgab

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-bj-gab 37847	. . 3 ⊢ {𝐵 ∣ 𝑥 ∣ 𝜓} = {𝑦 ∣ ∃𝑥(𝐵 = 𝑦 ∧ 𝜓)}
2	1	eleq2i 2853	. 2 ⊢ (𝐴 ∈ {𝐵 ∣ 𝑥 ∣ 𝜓} ↔ 𝐴 ∈ {𝑦 ∣ ∃𝑥(𝐵 = 𝑦 ∧ 𝜓)})
3		bj-elgab.ex	. . . 4 ⊢ (𝜑 → 𝐴 ∈ 𝑉)
4		bj-elgab.nf	. . . . . . . . 9 ⊢ (𝜑 → ∀𝑥𝜑)
5	4	adantr 486	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦 = 𝐴) → ∀𝑥𝜑)
6		bj-elgab.nfa	. . . . . . . . . 10 ⊢ (𝜑 → Ⅎ𝑥𝐴)
7		nfcvd 2924	. . . . . . . . . . . 12 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥𝑦)
8		id 23	. . . . . . . . . . . 12 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥𝐴)
9	7, 8	nfeqd 2933	. . . . . . . . . . 11 ⊢ (Ⅎ𝑥𝐴 → Ⅎ𝑥 𝑦 = 𝐴)
10	9	nf5rd 2233	. . . . . . . . . 10 ⊢ (Ⅎ𝑥𝐴 → (𝑦 = 𝐴 → ∀𝑥 𝑦 = 𝐴))
11	6, 10	syl 18	. . . . . . . . 9 ⊢ (𝜑 → (𝑦 = 𝐴 → ∀𝑥 𝑦 = 𝐴))
12	11	imp 412	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑦 = 𝐴) → ∀𝑥 𝑦 = 𝐴)
13		19.26 1903	. . . . . . . 8 ⊢ (∀𝑥(𝜑 ∧ 𝑦 = 𝐴) ↔ (∀𝑥𝜑 ∧ ∀𝑥 𝑦 = 𝐴))
14	5, 12, 13	sylanbrc 595	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 = 𝐴) → ∀𝑥(𝜑 ∧ 𝑦 = 𝐴))
15		eqeq2 2773	. . . . . . . . . 10 ⊢ (𝑦 = 𝐴 → (𝐵 = 𝑦 ↔ 𝐵 = 𝐴))
16		eqcom 2768	. . . . . . . . . 10 ⊢ (𝐵 = 𝐴 ↔ 𝐴 = 𝐵)
17	15, 16	bitrdi 290	. . . . . . . . 9 ⊢ (𝑦 = 𝐴 → (𝐵 = 𝑦 ↔ 𝐴 = 𝐵))
18	17	anbi1d 643	. . . . . . . 8 ⊢ (𝑦 = 𝐴 → ((𝐵 = 𝑦 ∧ 𝜓) ↔ (𝐴 = 𝐵 ∧ 𝜓)))
19	18	adantl 487	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑦 = 𝐴) → ((𝐵 = 𝑦 ∧ 𝜓) ↔ (𝐴 = 𝐵 ∧ 𝜓)))
20	14, 19	exbidh 1900	. . . . . 6 ⊢ ((𝜑 ∧ 𝑦 = 𝐴) → (∃𝑥(𝐵 = 𝑦 ∧ 𝜓) ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓)))
21	20	ex 418	. . . . 5 ⊢ (𝜑 → (𝑦 = 𝐴 → (∃𝑥(𝐵 = 𝑦 ∧ 𝜓) ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓))))
22	21	alrimiv 1960	. . . 4 ⊢ (𝜑 → ∀𝑦(𝑦 = 𝐴 → (∃𝑥(𝐵 = 𝑦 ∧ 𝜓) ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓))))
23		elabgt 3626	. . . 4 ⊢ ((𝐴 ∈ 𝑉 ∧ ∀𝑦(𝑦 = 𝐴 → (∃𝑥(𝐵 = 𝑦 ∧ 𝜓) ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓)))) → (𝐴 ∈ {𝑦 ∣ ∃𝑥(𝐵 = 𝑦 ∧ 𝜓)} ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓)))
24	3, 22, 23	syl2anc 596	. . 3 ⊢ (𝜑 → (𝐴 ∈ {𝑦 ∣ ∃𝑥(𝐵 = 𝑦 ∧ 𝜓)} ↔ ∃𝑥(𝐴 = 𝐵 ∧ 𝜓)))
25		bj-elgab.is	. . 3 ⊢ (𝜑 → (∃𝑥(𝐴 = 𝐵 ∧ 𝜓) ↔ 𝜒))
26	24, 25	bitrd 282	. 2 ⊢ (𝜑 → (𝐴 ∈ {𝑦 ∣ ∃𝑥(𝐵 = 𝑦 ∧ 𝜓)} ↔ 𝜒))
27	2, 26	bitrid 286	1 ⊢ (𝜑 → (𝐴 ∈ {𝐵 ∣ 𝑥 ∣ 𝜓} ↔ 𝜒))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1568   = wceq 1570  ∃wex 1812   ∈ wcel 2145  {cab 2739  Ⅎwnfc 2908  {bj-cgab 37846

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-10 2178  ax-11 2194  ax-12 2213  ax-ext 2733

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1573  df-ex 1813  df-nf 1817  df-sb 2100  df-clab 2740  df-cleq 2753  df-clel 2836  df-nfc 2910  df-bj-gab 37847

This theorem is used by:  bj-gabima  37853