Metamath Proof Explorer


Theorem 3mix2

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

Ref Expression
Assertion 3mix2 ( 𝜑 → ( 𝜓𝜑𝜒 ) )

Proof

Step Hyp Ref Expression
1 3mix1 ( 𝜑 → ( 𝜑𝜒𝜓 ) )
2 3orrot ( ( 𝜓𝜑𝜒 ) ↔ ( 𝜑𝜒𝜓 ) )
3 1 2 sylibr ( 𝜑 → ( 𝜓𝜑𝜒 ) )