Metamath Proof Explorer


Theorem 3jcad

Description: Deduction conjoining the consequents of three implications. (Contributed by NM, 25-Sep-2005)

Ref Expression
Hypotheses 3jcad.1 ( 𝜑 → ( 𝜓𝜒 ) )
3jcad.2 ( 𝜑 → ( 𝜓𝜃 ) )
3jcad.3 ( 𝜑 → ( 𝜓𝜏 ) )
Assertion 3jcad ( 𝜑 → ( 𝜓 → ( 𝜒𝜃𝜏 ) ) )

Proof

Step Hyp Ref Expression
1 3jcad.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 3jcad.2 ( 𝜑 → ( 𝜓𝜃 ) )
3 3jcad.3 ( 𝜑 → ( 𝜓𝜏 ) )
4 1 imp ( ( 𝜑𝜓 ) → 𝜒 )
5 2 imp ( ( 𝜑𝜓 ) → 𝜃 )
6 3 imp ( ( 𝜑𝜓 ) → 𝜏 )
7 4 5 6 3jca ( ( 𝜑𝜓 ) → ( 𝜒𝜃𝜏 ) )
8 7 ex ( 𝜑 → ( 𝜓 → ( 𝜒𝜃𝜏 ) ) )