Metamath Proof Explorer


Theorem wl-luk-a1i

Description: Inference rule. Copy of a1i with a different proof. (Contributed by Wolf Lammen, 17-Dec-2018) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypothesis wl-luk-a1i.1
|- ph
Assertion wl-luk-a1i
|- ( ps -> ph )

Proof

Step Hyp Ref Expression
1 wl-luk-a1i.1
 |-  ph
2 1 wl-luk-pm2.24i
 |-  ( -. ph -> -. ps )
3 2 wl-luk-con4i
 |-  ( ps -> ph )