Theorem fald

Description: Refutation of falsity, in deduction form. (Contributed by Giovanni Mascellani, 24-Mar-2018)

	Ref	Expression
Assertion	fald	⊢ ( 𝜃 → ¬ ⊥ )

Proof

Step	Hyp	Ref	Expression
1		fal	⊢ ¬ ⊥
2	1	a1i	⊢ ( 𝜃 → ¬ ⊥ )