Theorem intnanrt

Description: Introduction of conjunct inside of a contradiction. Would be used in elfvov1 . (Contributed by SN, 18-May-2025)

	Ref	Expression
Assertion	intnanrt	$$⊢\neg \phi \to \neg \left(\phi \wedge \psi \right)$$

Proof

Step	Hyp	Ref	Expression
1		simpl	$$⊢\left(\phi \wedge \psi \right)\to \phi$$
2	1	con3i	$$⊢\neg \phi \to \neg \left(\phi \wedge \psi \right)$$