Theorem nfim1 1503

Description: A closed form of nfim 1504. (Contributed by NM, 5-Aug-1993.) (Revised by Mario Carneiro, 24-Sep-2016.) (Proof shortened by Wolf Lammen, 2-Jan-2018.)

Hypotheses

Ref	Expression
nfim1.1	⊢ Ⅎ𝑥𝜑
nfim1.2	⊢ (𝜑 → Ⅎ𝑥𝜓)

Assertion

Ref	Expression
nfim1	⊢ Ⅎ𝑥(𝜑 → 𝜓)

Proof of Theorem nfim1

Step	Hyp	Ref	Expression
1		nfim1.1	. . . 4 ⊢ Ⅎ𝑥𝜑
2	1	nfri 1452	. . 3 ⊢ (𝜑 → ∀𝑥𝜑)
3		nfim1.2	. . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜓)
4	3	nfrd 1453	. . 3 ⊢ (𝜑 → (𝜓 → ∀𝑥𝜓))
5	2, 4	hbim1 1502	. 2 ⊢ ((𝜑 → 𝜓) → ∀𝑥(𝜑 → 𝜓))
6	5	nfi 1391	1 ⊢ Ⅎ𝑥(𝜑 → 𝜓)

Syntax hints:   → wi 4  Ⅎwnf 1389

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-5 1376  ax-gen 1378  ax-4 1440  ax-ial 1467  ax-i5r 1468

This theorem depends on definitions:  df-bi 115  df-nf 1390

This theorem is referenced by:  nfim  1504  cbv1  1672  hbsbd  1899