Metamath Proof Explorer

Theorem bnj658

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

		Ref	Expression
	Assertion	bnj658	$⊢ (φ \land ψ \land χ \land θ) \to (φ \land ψ \land χ)$

Step	Hyp	Ref	Expression
1		df-bnj17	$⊢ (φ \land ψ \land χ \land θ) \leftrightarrow ((φ \land ψ \land χ) \land θ)$
2	1	simplbi	$⊢ (φ \land ψ \land χ \land θ) \to (φ \land ψ \land χ)$