Theorem alcoms 1529

Description: Swap quantifiers in an antecedent. (Contributed by NM, 11-May-1993.)

Hypothesis

Ref	Expression
alcoms.1	⊢ (∀𝑥∀𝑦𝜑 → 𝜓)

Assertion

Ref	Expression
alcoms	⊢ (∀𝑦∀𝑥𝜑 → 𝜓)

Proof of Theorem alcoms

Step	Hyp	Ref	Expression
1		ax-7 1501	. 2 ⊢ (∀𝑦∀𝑥𝜑 → ∀𝑥∀𝑦𝜑)
2		alcoms.1	. 2 ⊢ (∀𝑥∀𝑦𝜑 → 𝜓)
3	1, 2	syl 14	1 ⊢ (∀𝑦∀𝑥𝜑 → 𝜓)

This proof depends on syntax axioms:   → wi 4  ∀wal 1400

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-7 1501

This theorem is used by:  bj-nfalt  16804