Theorem bj-falor

Description: Dual of truan (which has biconditional reversed). (Contributed by BJ, 26-Oct-2019) (Proof modification is discouraged.)

	Ref	Expression
Assertion	bj-falor	⊢ ( 𝜑 ↔ ( ⊥ ∨ 𝜑 ) )

Proof

Step	Hyp	Ref	Expression
1		fal	⊢ ¬ ⊥
2	1	biorfi	⊢ ( 𝜑 ↔ ( ⊥ ∨ 𝜑 ) )