Theorem notnoti 145

Description: Inference associated with notnot 144. (Contributed by NM, 27-Feb-2008.)

Hypothesis

Ref	Expression
notnoti.1	⊢ 𝜑

Assertion

Ref	Expression
notnoti	⊢ ¬ ¬ 𝜑

Proof of Theorem notnoti

Step	Hyp	Ref	Expression
1		notnoti.1	. 2 ⊢ 𝜑
2		notnot 144	. 2 ⊢ (𝜑 → ¬ ¬ 𝜑)
3	1, 2	ax-mp 5	1 ⊢ ¬ ¬ 𝜑

Syntax hints:  ¬ wn 3

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem is referenced by:  nbn3  376  fal  1551  trunortruOLD  1587  trunorfalOLD  1589  ax6dgen  2132  dfnul2  4295  mdegleb  24660  nexntru  33754  amosym1  33776  ifpdfan2  39835  aisbnaxb  43154