Theorem aaanh 1478

Description: Rearrange universal quantifiers. (Contributed by NM, 12-Aug-1993.)

Hypotheses

Ref	Expression
aaanh.1	⊢ (𝜑 → ∀𝑦𝜑)
aaanh.2	⊢ (𝜓 → ∀𝑥𝜓)

Assertion

Ref	Expression
aaanh	⊢ (∀𝑥∀𝑦(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ ∀𝑦𝜓))

Proof of Theorem aaanh

Step	Hyp	Ref	Expression
1		aaanh.1	. . . 4 ⊢ (𝜑 → ∀𝑦𝜑)
2	1	19.28h 1454	. . 3 ⊢ (∀𝑦(𝜑 ∧ 𝜓) ↔ (𝜑 ∧ ∀𝑦𝜓))
3	2	albii 1359	. 2 ⊢ (∀𝑥∀𝑦(𝜑 ∧ 𝜓) ↔ ∀𝑥(𝜑 ∧ ∀𝑦𝜓))
4		aaanh.2	. . . 4 ⊢ (𝜓 → ∀𝑥𝜓)
5	4	hbal 1366	. . 3 ⊢ (∀𝑦𝜓 → ∀𝑥∀𝑦𝜓)
6	5	19.27h 1452	. 2 ⊢ (∀𝑥(𝜑 ∧ ∀𝑦𝜓) ↔ (∀𝑥𝜑 ∧ ∀𝑦𝜓))
7	3, 6	bitri 173	1 ⊢ (∀𝑥∀𝑦(𝜑 ∧ 𝜓) ↔ (∀𝑥𝜑 ∧ ∀𝑦𝜓))

Syntax hints:   → wi 4   ∧ wa 97   ↔ wb 98  ∀wal 1241

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-7 1337  ax-gen 1338  ax-4 1400

This theorem depends on definitions:  df-bi 110

This theorem is referenced by:  mo23  1941  2eu4  1993