Currently I have to learn Coq and don't know how to deal with an
As an example, as simple as it is, I don't see how to prove:
Theorem T0: x \/ ~x.
I would really appreciate it, if someone could help me.
For reference I use this cheat sheet.
Also an example of a proof I have in mind: Here for double negation:
Require Import Classical_Prop. Parameters x: Prop. Theorem T7: (~~x) -> x. intro H. apply NNPP. exact H. Qed.