Theorem notnotriOLD 127

Description: Obsolete proof of notnotri 126 as of 15-Jul-2021 . (Contributed by NM, 27-Feb-2008.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypothesis

Ref	Expression
notnotri.1	⊢ ¬ ¬ 𝜑

Assertion

Ref	Expression
notnotriOLD	⊢ 𝜑

Proof of Theorem notnotriOLD

Step	Hyp	Ref	Expression
1		notnotri.1	. 2 ⊢ ¬ ¬ 𝜑
2		notnotr 125	. 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: (None)