Metamath Proof Explorer


Theorem bifal

Description: A contradiction is equivalent to falsehood. (Contributed by Mario Carneiro, 9-May-2015)

Ref Expression
Hypothesis bifal.1 ¬ 𝜑
Assertion bifal ( 𝜑 ↔ ⊥ )

Proof

Step Hyp Ref Expression
1 bifal.1 ¬ 𝜑
2 fal ¬ ⊥
3 1 2 2false ( 𝜑 ↔ ⊥ )