Theorem eliind 45425

Description: Membership in indexed intersection. (Contributed by Glauco Siliprandi, 24-Dec-2020.)

Hypotheses

Ref	Expression
eliind.a	⊢ (𝜑 → 𝐴 ∈ ∩ 𝑥 ∈ 𝐵 𝐶)
eliind.k	⊢ (𝜑 → 𝐾 ∈ 𝐵)
eliind.d	⊢ (𝑥 = 𝐾 → (𝐴 ∈ 𝐶 ↔ 𝐴 ∈ 𝐷))

Assertion

Ref	Expression
eliind	⊢ (𝜑 → 𝐴 ∈ 𝐷)

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝐷   𝑥,𝐾

Allowed substitution hints:   𝜑(𝑥)   𝐶(𝑥)

Proof of Theorem eliind

Step	Hyp	Ref	Expression
1		eliind.d	. 2 ⊢ (𝑥 = 𝐾 → (𝐴 ∈ 𝐶 ↔ 𝐴 ∈ 𝐷))
2		eliind.a	. . 3 ⊢ (𝜑 → 𝐴 ∈ ∩ 𝑥 ∈ 𝐵 𝐶)
3		eliin 4953	. . . 4 ⊢ (𝐴 ∈ ∩ 𝑥 ∈ 𝐵 𝐶 → (𝐴 ∈ ∩ 𝑥 ∈ 𝐵 𝐶 ↔ ∀𝑥 ∈ 𝐵 𝐴 ∈ 𝐶))
4	2, 3	syl 17	. . 3 ⊢ (𝜑 → (𝐴 ∈ ∩ 𝑥 ∈ 𝐵 𝐶 ↔ ∀𝑥 ∈ 𝐵 𝐴 ∈ 𝐶))
5	2, 4	mpbid 232	. 2 ⊢ (𝜑 → ∀𝑥 ∈ 𝐵 𝐴 ∈ 𝐶)
6		eliind.k	. 2 ⊢ (𝜑 → 𝐾 ∈ 𝐵)
7	1, 5, 6	rspcdva 3579	1 ⊢ (𝜑 → 𝐴 ∈ 𝐷)

Syntax hints:   → wi 4   ↔ wb 206   = wceq 1542   ∈ wcel 2114  ∀wral 3052  ∩ ciin 4949

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-ext 2709

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1545  df-ex 1782  df-sb 2069  df-clab 2716  df-cleq 2729  df-clel 2812  df-ral 3053  df-iin 4951

This theorem is referenced by:  iooiinioc  45910  hspdifhsp  46968  smflimlem3  47125  smfsuplem1  47163  smflimsuplem4  47175