PHIL 012 Chapter 5: Chapter 5
Document Summary
Proof: a finite sequence of wffs that is either a premise, an assumption, or the result of preceding wffs and derivation rules the end of a proof is its conclusion. Derivation rule: an explicitly stated rule that allows a proof to move forward. P ^ r r means that there is a proof that r is a syntactic consequence. R means that there is a proof of r or that r is a theorem. Once the conclusion of a proof is reached, the proof is finished of p ^ r. Premises and goal the wffs preceding the turnstile serve as premises and are justified by the symbol. P the wff following the turnstile serves as the goal the proof must find a way of getting from the premises to the goal. Pd is intelim, meaning for every operator there is an introduction and elimination rule. Conjunction introduction (^i) from "p" and "q" derive "p ^ q" or "q ^ p"
