Theorem intabs 5341

Description: Absorption of a redundant conjunct in the intersection of a class abstraction. (Contributed by NM, 3-Jul-2005.)

Hypotheses

Ref	Expression
intabs.1	⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓))
intabs.2	⊢ (𝑥 = ∩ {𝑦 ∣ 𝜓} → (𝜑 ↔ 𝜒))
intabs.3	⊢ (∩ {𝑦 ∣ 𝜓} ⊆ 𝐴 ∧ 𝜒)

Assertion

Ref	Expression
intabs	⊢ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} = ∩ {𝑥 ∣ 𝜑}

Distinct variable groups:   𝑥,𝑦   𝑥,𝐴   𝜑,𝑦   𝜓,𝑥   𝜒,𝑥

Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑦)   𝜒(𝑦)   𝐴(𝑦)

Proof of Theorem intabs

Step	Hyp	Ref	Expression
1		sseq1 4006	. . . . . 6 ⊢ (𝑥 = ∩ {𝑦 ∣ 𝜓} → (𝑥 ⊆ 𝐴 ↔ ∩ {𝑦 ∣ 𝜓} ⊆ 𝐴))
2		intabs.2	. . . . . 6 ⊢ (𝑥 = ∩ {𝑦 ∣ 𝜓} → (𝜑 ↔ 𝜒))
3	1, 2	anbi12d 629	. . . . 5 ⊢ (𝑥 = ∩ {𝑦 ∣ 𝜓} → ((𝑥 ⊆ 𝐴 ∧ 𝜑) ↔ (∩ {𝑦 ∣ 𝜓} ⊆ 𝐴 ∧ 𝜒)))
4		intabs.3	. . . . 5 ⊢ (∩ {𝑦 ∣ 𝜓} ⊆ 𝐴 ∧ 𝜒)
5	3, 4	intmin3 4979	. . . 4 ⊢ (∩ {𝑦 ∣ 𝜓} ∈ V → ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑦 ∣ 𝜓})
6		intnex 5337	. . . . 5 ⊢ (¬ ∩ {𝑦 ∣ 𝜓} ∈ V ↔ ∩ {𝑦 ∣ 𝜓} = V)
7		ssv 4005	. . . . . 6 ⊢ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ V
8		sseq2 4007	. . . . . 6 ⊢ (∩ {𝑦 ∣ 𝜓} = V → (∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑦 ∣ 𝜓} ↔ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ V))
9	7, 8	mpbiri 257	. . . . 5 ⊢ (∩ {𝑦 ∣ 𝜓} = V → ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑦 ∣ 𝜓})
10	6, 9	sylbi 216	. . . 4 ⊢ (¬ ∩ {𝑦 ∣ 𝜓} ∈ V → ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑦 ∣ 𝜓})
11	5, 10	pm2.61i 182	. . 3 ⊢ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑦 ∣ 𝜓}
12		intabs.1	. . . . 5 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓))
13	12	cbvabv 2803	. . . 4 ⊢ {𝑥 ∣ 𝜑} = {𝑦 ∣ 𝜓}
14	13	inteqi 4953	. . 3 ⊢ ∩ {𝑥 ∣ 𝜑} = ∩ {𝑦 ∣ 𝜓}
15	11, 14	sseqtrri 4018	. 2 ⊢ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ ∩ {𝑥 ∣ 𝜑}
16		simpr 483	. . . 4 ⊢ ((𝑥 ⊆ 𝐴 ∧ 𝜑) → 𝜑)
17	16	ss2abi 4062	. . 3 ⊢ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ {𝑥 ∣ 𝜑}
18		intss 4972	. . 3 ⊢ ({𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} ⊆ {𝑥 ∣ 𝜑} → ∩ {𝑥 ∣ 𝜑} ⊆ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)})
19	17, 18	ax-mp 5	. 2 ⊢ ∩ {𝑥 ∣ 𝜑} ⊆ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)}
20	15, 19	eqssi 3997	1 ⊢ ∩ {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ 𝜑)} = ∩ {𝑥 ∣ 𝜑}

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 394   = wceq 1539   ∈ wcel 2104  {cab 2707  Vcvv 3472   ⊆ wss 3947  ∩ cint 4949

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1911  ax-6 1969  ax-7 2009  ax-8 2106  ax-9 2114  ax-ext 2701  ax-sep 5298

This theorem depends on definitions:  df-bi 206  df-an 395  df-tru 1542  df-fal 1552  df-ex 1780  df-sb 2066  df-clab 2708  df-cleq 2722  df-clel 2808  df-ne 2939  df-ral 3060  df-rex 3069  df-rab 3431  df-v 3474  df-dif 3950  df-in 3954  df-ss 3964  df-nul 4322  df-int 4950

This theorem is referenced by:  dfnn3  12230