Metamath Proof Explorer


Theorem 3mix3

Description: Introduction in triple disjunction. (Contributed by NM, 4-Apr-1995)

Ref Expression
Assertion 3mix3 φψχφ

Proof

Step Hyp Ref Expression
1 3mix1 φφψχ
2 3orrot φψχψχφ
3 1 2 sylib φψχφ