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Metamath Proof Explorer

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	$⊢ \neg (φ \to ψ) \to (χ \to \neg ψ)$

Step	Hyp	Ref	Expression
1		conax1	$⊢ \neg (φ \to ψ) \to \neg ψ$
2	1	a1d	$⊢ \neg (φ \to ψ) \to (χ \to \neg ψ)$