Metamath Proof Explorer

Theorem axin2

Description: 'Not' elimination (intuitionistic logic axiom ax-in2). (Contributed by Jim Kingdon, 21-May-2018) (New usage is discouraged.)

Ref Expression
Assertion axin2 
|- ( -. ph -> ( ph -> ps ) )

Proof

Step Hyp Ref Expression
1 pm2.21 
 |-  ( -. ph -> ( ph -> ps ) )