Theorem ralcomf 3310

Description: Commutation of restricted universal quantifiers. (Contributed by Mario Carneiro, 14-Oct-2016.)

Hypotheses

Ref	Expression
ralcomf.1	⊢ Ⅎ𝑦𝐴
ralcomf.2	⊢ Ⅎ𝑥𝐵

Assertion

Ref	Expression
ralcomf	⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ ∀𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐴 𝜑)

Distinct variable group:   𝑥,𝑦

Allowed substitution hints:   𝜑(𝑥,𝑦)   𝐴(𝑥,𝑦)   𝐵(𝑥,𝑦)

Proof of Theorem ralcomf

Step	Hyp	Ref	Expression
1		ancomst 468	. . . 4 ⊢ (((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑) ↔ ((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑))
2	1	2albii 1822	. . 3 ⊢ (∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑) ↔ ∀𝑥∀𝑦((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑))
3		alcom 2160	. . 3 ⊢ (∀𝑥∀𝑦((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑) ↔ ∀𝑦∀𝑥((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑))
4	2, 3	bitri 278	. 2 ⊢ (∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑) ↔ ∀𝑦∀𝑥((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑))
5		ralcomf.1	. . 3 ⊢ Ⅎ𝑦𝐴
6	5	r2alf 3186	. 2 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ ∀𝑥∀𝑦((𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵) → 𝜑))
7		ralcomf.2	. . 3 ⊢ Ⅎ𝑥𝐵
8	7	r2alf 3186	. 2 ⊢ (∀𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐴 𝜑 ↔ ∀𝑦∀𝑥((𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴) → 𝜑))
9	4, 6, 8	3bitr4i 306	1 ⊢ (∀𝑥 ∈ 𝐴 ∀𝑦 ∈ 𝐵 𝜑 ↔ ∀𝑦 ∈ 𝐵 ∀𝑥 ∈ 𝐴 𝜑)

Syntax hints:   → wi 4   ↔ wb 209   ∧ wa 399  ∀wal 1536   ∈ wcel 2111  Ⅎwnfc 2936  ∀wral 3106

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 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-11 2158  ax-12 2175

This theorem depends on definitions:  df-bi 210  df-an 400  df-ex 1782  df-nf 1786  df-clel 2870  df-nfc 2938  df-ral 3111

This theorem is referenced by:  ssiinf  4941  ralcom4f  30240