Metamath Proof Explorer


Theorem sylan9r

Description: Nested syllogism inference conjoining dissimilar antecedents. (Contributed by NM, 14-May-1993)

Ref Expression
Hypotheses sylan9r.1
|- ( ph -> ( ps -> ch ) )
sylan9r.2
|- ( th -> ( ch -> ta ) )
Assertion sylan9r
|- ( ( th /\ ph ) -> ( ps -> ta ) )

Proof

Step Hyp Ref Expression
1 sylan9r.1
 |-  ( ph -> ( ps -> ch ) )
2 sylan9r.2
 |-  ( th -> ( ch -> ta ) )
3 1 2 syl9r
 |-  ( th -> ( ph -> ( ps -> ta ) ) )
4 3 imp
 |-  ( ( th /\ ph ) -> ( ps -> ta ) )