Theorem bnj706

Description: /\ -manipulation. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Hypothesis	bnj706.1	$$⊢\psi \to \tau$$
Assertion	bnj706	$$⊢\left(\phi \wedge \psi \wedge \chi \wedge \theta \right)\to \tau$$

Proof

Step	Hyp	Ref	Expression
1		bnj706.1	$$⊢\psi \to \tau$$
2		bnj643	$$⊢\left(\phi \wedge \psi \wedge \chi \wedge \theta \right)\to \psi$$
3	2 1	syl	$$⊢\left(\phi \wedge \psi \wedge \chi \wedge \theta \right)\to \tau$$