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Metamath Proof Explorer

Theorem intnan

Description: Introduction of conjunct inside of a contradiction. (Contributed by NM, 16-Sep-1993)

		Ref	Expression
	Hypothesis	intnan.1	$⊢ \neg φ$
	Assertion	intnan	$⊢ \neg (ψ \land φ)$

Step	Hyp	Ref	Expression
1		intnan.1	$⊢ \neg φ$
2		simpr	$⊢ (ψ \land φ) \to φ$
3	1 2	mto	$⊢ \neg (ψ \land φ)$