Theorem ra5 3122

Description: Restricted quantifier version of Axiom 5 of [Mendelson] p. 69. This is an axiom of a predicate calculus for a restricted domain. Compare the unrestricted stdpc5 1633. (Contributed by NM, 16-Jan-2004.)

Hypothesis

Ref	Expression
ra5.1	⊢ Ⅎ𝑥𝜑

Assertion

Ref	Expression
ra5	⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) → (𝜑 → ∀𝑥 ∈ 𝐴 𝜓))

Proof of Theorem ra5

Step	Hyp	Ref	Expression
1		df-ral 2516	. . . 4 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) ↔ ∀𝑥(𝑥 ∈ 𝐴 → (𝜑 → 𝜓)))
2		bi2.04 248	. . . . 5 ⊢ ((𝑥 ∈ 𝐴 → (𝜑 → 𝜓)) ↔ (𝜑 → (𝑥 ∈ 𝐴 → 𝜓)))
3	2	albii 1519	. . . 4 ⊢ (∀𝑥(𝑥 ∈ 𝐴 → (𝜑 → 𝜓)) ↔ ∀𝑥(𝜑 → (𝑥 ∈ 𝐴 → 𝜓)))
4	1, 3	bitri 184	. . 3 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) ↔ ∀𝑥(𝜑 → (𝑥 ∈ 𝐴 → 𝜓)))
5		ra5.1	. . . 4 ⊢ Ⅎ𝑥𝜑
6	5	stdpc5 1633	. . 3 ⊢ (∀𝑥(𝜑 → (𝑥 ∈ 𝐴 → 𝜓)) → (𝜑 → ∀𝑥(𝑥 ∈ 𝐴 → 𝜓)))
7	4, 6	sylbi 121	. 2 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) → (𝜑 → ∀𝑥(𝑥 ∈ 𝐴 → 𝜓)))
8		df-ral 2516	. 2 ⊢ (∀𝑥 ∈ 𝐴 𝜓 ↔ ∀𝑥(𝑥 ∈ 𝐴 → 𝜓))
9	7, 8	imbitrrdi 162	1 ⊢ (∀𝑥 ∈ 𝐴 (𝜑 → 𝜓) → (𝜑 → ∀𝑥 ∈ 𝐴 𝜓))

Syntax hints:   → wi 4  ∀wal 1396  Ⅎwnf 1509   ∈ wcel 2202  ∀wral 2511

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1496  ax-gen 1498  ax-4 1559  ax-ial 1583  ax-i5r 1584

This theorem depends on definitions:  df-bi 117  df-nf 1510  df-ral 2516

This theorem is referenced by: (None)