Metamath Proof Explorer


Theorem jarli

Description: Inference associated with jarl . Partial converse of ja (the other partial converse being jarri ). (Contributed by Wolf Lammen, 4-Oct-2013)

Ref Expression
Hypothesis jarli.1
|- ( ( ph -> ps ) -> ch )
Assertion jarli
|- ( -. ph -> ch )

Proof

Step Hyp Ref Expression
1 jarli.1
 |-  ( ( ph -> ps ) -> ch )
2 pm2.21
 |-  ( -. ph -> ( ph -> ps ) )
3 2 1 syl
 |-  ( -. ph -> ch )