Theorem simp2l

Description: Simplification of triple conjunction. (Contributed by NM, 9-Nov-2011)

	Ref	Expression
Assertion	simp2l	$$⊢\left(\phi \wedge \left(\psi \wedge \chi \right)\wedge \theta \right)\to \psi$$

Proof

Step	Hyp	Ref	Expression
1		simpl	$$⊢\left(\psi \wedge \chi \right)\to \psi$$
2	1	3ad2ant2	$$⊢\left(\phi \wedge \left(\psi \wedge \chi \right)\wedge \theta \right)\to \psi$$