Theorem 19.36i 1724

Description: Inference from Theorem 19.36 of [Margaris] p. 90. (Contributed by NM, 5-Aug-1993.) (Revised by NM, 2-Feb-2015.)

Hypotheses

Ref	Expression
19.36i.1	⊢ Ⅎ𝑥𝜓
19.36i.2	⊢ ∃𝑥(𝜑 → 𝜓)

Assertion

Ref	Expression
19.36i	⊢ (∀𝑥𝜑 → 𝜓)

Proof of Theorem 19.36i

Step	Hyp	Ref	Expression
1		19.36i.2	. . 3 ⊢ ∃𝑥(𝜑 → 𝜓)
2	1	19.35i 1678	. 2 ⊢ (∀𝑥𝜑 → ∃𝑥𝜓)
3		19.36i.1	. . 3 ⊢ Ⅎ𝑥𝜓
4		id 19	. . 3 ⊢ (𝜓 → 𝜓)
5	3, 4	exlimi 1647	. 2 ⊢ (∃𝑥𝜓 → 𝜓)
6	2, 5	syl 14	1 ⊢ (∀𝑥𝜑 → 𝜓)

This proof depends on syntax axioms:   → wi 4  ∀wal 1400  Ⅎwnf 1513  ∃wex 1545

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-4 1563  ax-ial 1587

This proof depends on definitions:  df-bi 117  df-nf 1514

This theorem is used by:  spimfv  1751  19.36aiv  1957  vtoclf  2876