Theorem con5i

Description: Inference form of con5 . (Contributed by Alan Sare, 21-Apr-2013) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypothesis	con5i.1	$$⊢\phi \leftrightarrow \neg \psi$$
Assertion	con5i	$$⊢\neg \phi \to \psi$$

Proof

Step	Hyp	Ref	Expression
1		con5i.1	$$⊢\phi \leftrightarrow \neg \psi$$
2		con5	$$⊢\left(\phi \leftrightarrow \neg \psi \right)\to \left(\neg \phi \to \psi \right)$$
3	1 2	ax-mp	$$⊢\neg \phi \to \psi$$