Theorem 19.36i 2267

Description: Inference associated with 19.36 2266. See 19.36iv 1978 for a version requiring fewer axioms. (Contributed by NM, 24-Jun-1993.)

Hypotheses

Ref	Expression
19.36.1	⊢ 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	. 2 ⊢ ∃𝑥(𝜑 → 𝜓)
2		19.36.1	. . 3 ⊢ Ⅎ𝑥𝜓
3	2	19.36 2266	. 2 ⊢ (∃𝑥(𝜑 → 𝜓) ↔ (∀𝑥𝜑 → 𝜓))
4	1, 3	mpbi 233	1 ⊢ (∀𝑥𝜑 → 𝜓)

This proof depends on syntax axioms:   → wi 4  ∀wal 1567  ∃wex 1811  Ⅎwnf 1815

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-12 2212

This proof depends on definitions:  df-bi 210  df-ex 1812  df-nf 1816

This theorem is used by:  spimfv  2275  spim  2416  bj-vtoclf  37923