Theorem syl3anl3

Description: A syllogism inference. (Contributed by NM, 24-Feb-2005)

	Ref	Expression
Hypotheses	syl3anl3.1	$$⊢\phi \to \theta$$
	syl3anl3.2	$$⊢\left(\left(\psi \wedge \chi \wedge \theta \right)\wedge \tau \right)\to \eta$$
Assertion	syl3anl3	$$⊢\left(\left(\psi \wedge \chi \wedge \phi \right)\wedge \tau \right)\to \eta$$

Proof

Step	Hyp	Ref	Expression
1		syl3anl3.1	$$⊢\phi \to \theta$$
2		syl3anl3.2	$$⊢\left(\left(\psi \wedge \chi \wedge \theta \right)\wedge \tau \right)\to \eta$$
3	1	3anim3i	$$⊢\left(\psi \wedge \chi \wedge \phi \right)\to \left(\psi \wedge \chi \wedge \theta \right)$$
4	3 2	sylan	$$⊢\left(\left(\psi \wedge \chi \wedge \phi \right)\wedge \tau \right)\to \eta$$