Theorem anidms

Description: Inference from idempotent law for conjunction. (Contributed by NM, 15-Jun-1994)

	Ref	Expression
Hypothesis	anidms.1	$$⊢\left(\phi \wedge \phi \right)\to \psi$$
Assertion	anidms	$$⊢\phi \to \psi$$

Proof

Step	Hyp	Ref	Expression
1		anidms.1	$$⊢\left(\phi \wedge \phi \right)\to \psi$$
2	1	ex	$$⊢\phi \to \left(\phi \to \psi \right)$$
3	2	pm2.43i	$$⊢\phi \to \psi$$