Theorem conax1k

Description: Weakening of conax1 . General instance of pm2.51 and of pm2.52 . (Contributed by BJ, 28-Oct-2023)

	Ref	Expression
Assertion	conax1k	$$⊢\neg \left(\phi \to \psi \right)\to \left(\chi \to \neg \psi \right)$$

Proof

Step	Hyp	Ref	Expression
1		conax1	$$⊢\neg \left(\phi \to \psi \right)\to \neg \psi$$
2	1	a1d	$$⊢\neg \left(\phi \to \psi \right)\to \left(\chi \to \neg \psi \right)$$