is derived. Please let me know if you need any clarification. I'm always happy to answer your questions.
*And finally, please don't forget to give me a review in the end. I would be highly appreciate that.

I use the rule ~(X → Y) ∴ ~X v Y for all logical expressions X, Y to convert ∼(P→Q)→Q to only "AND" and "OR" form, which then allows me to add. The final expression turns out to be ~P v Q which is precisely P → Q.