Metamath Proof Explorer


Theorem ainaiaandna

Description: Given a, a implies it is not the case a implies a self contradiction. (Contributed by Jarvin Udandy, 7-Sep-2020)

Ref Expression
Hypothesis ainaiaandna.1
|- ph
Assertion ainaiaandna
|- ( ph -> -. ( ph -> ( ph /\ -. ph ) ) )

Proof

Step Hyp Ref Expression
1 ainaiaandna.1
 |-  ph
2 1 atnaiana
 |-  -. ( ph -> ( ph /\ -. ph ) )
3 2 a1i
 |-  ( ph -> -. ( ph -> ( ph /\ -. ph ) ) )