notnoti - Metamath Proof Explorer

	Metamath Proof Explorer	< Previous Next > Nearby theorems
Mirrors > Home > MPE Home > Th. List > notnoti		Structured version Unicode version

Theorem notnoti 123

Description: Infer double negation. (Contributed by NM, 27-Feb-2008.)

**Hypothesis**
Ref	Expression
negbi.1

**Assertion**
Ref	Expression
notnoti

**Proof of Theorem notnoti**
Step	Hyp	Ref	Expression
1		negbi.1	. 2
2		notnot1 122	. 2
3	1, 2	ax-mp 5	1

Colors of variables: wff setvar class

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 348 fal 1388 ax6dgen 1808 mdegleb 22330 nextnt 29838 amosym1 29859 aisbnaxb 31940