Metamath Proof Explorer


Theorem simp21r

Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)

Ref Expression
Assertion simp21r τφψχθηψ

Proof

Step Hyp Ref Expression
1 simp1r φψχθψ
2 1 3ad2ant2 τφψχθηψ