(e) Show that $\vdash \lnot(p \lor \lnot p) \to p \land \lnot p$
(f) Show that $\models p \lor \lnot p$ and $\vdash p \lor \lnot p$. For the second part, you can assume (e), i.e. you can treat $\lnot (p \lor \lnot p) \to p \land \lnot p$ as an assumption.
The first part is natural deduction, I just can't figure out how to go about it, and the second part I'm really not sure about.
$$% I'll add a link because I'm not sure how to put the symbols. [https://imgur.com/a/ijaE1vQ] : https://imgur.com/a/ijaE1vQ$$