Theorem jarli

Description: Inference associated with jarl . Partial converse of ja (the other partial converse being jarri ). (Contributed by Wolf Lammen, 4-Oct-2013)

	Ref	Expression
Hypothesis	jarli.1	$$⊢\left(\phi \to \psi \right)\to \chi$$
Assertion	jarli	$$⊢\neg \phi \to \chi$$

Proof

Step	Hyp	Ref	Expression
1		jarli.1	$$⊢\left(\phi \to \psi \right)\to \chi$$
2		pm2.21	$$⊢\neg \phi \to \left(\phi \to \psi \right)$$
3	2 1	syl	$$⊢\neg \phi \to \chi$$