Metamath Proof Explorer


Theorem syl9r

Description: A nested syllogism inference with different antecedents. (Contributed by NM, 14-May-1993)

Ref Expression
Hypotheses syl9r.1
|- ( ph -> ( ps -> ch ) )
syl9r.2
|- ( th -> ( ch -> ta ) )
Assertion syl9r
|- ( th -> ( ph -> ( ps -> ta ) ) )

Proof

Step Hyp Ref Expression
1 syl9r.1
 |-  ( ph -> ( ps -> ch ) )
2 syl9r.2
 |-  ( th -> ( ch -> ta ) )
3 1 2 syl9
 |-  ( ph -> ( th -> ( ps -> ta ) ) )
4 3 com12
 |-  ( th -> ( ph -> ( ps -> ta ) ) )