So I have a problem where I need to solve the first part of an implication so that it works with the second part.
https://i.stack.imgur.com/xx5bE.jpg
This is the problem as given to me.
What i have gotten up to now is this:
(P ∧ Q → P) → ((P ∧ Q) ∨ R → P ∨ R)
←
P ∨ R → S
https://i.stack.imgur.com/LbEax.jpg
The three laws that are use are included on this page.
I have checked with prover9/mace4 and this transformation is valid, but I am unsure if it is actually the correct transformation.
I'm not sure if I understand your task correctly.
(EDIT: Apparently I really didn't - see comments)
Anyway, I made some substitutions using the definitions given in your first link:
Using those substitutions as assumptions, we could continue transforming as follows:
...here's where it's me who gets stuck. What are the "Métathéorème" hiding at 3.100? Are you by any chance allowed to use $(p \rightarrow p) \rightarrow p$ ?