PHIL 3 Lecture Notes - Lecture 11: Thanetian, Modus Tollens, Modus Ponens
Document Summary
/q. : valid applications, 1. (p * q) horseshoe (g * ~d). / g * ~d: 2. (k * d) v f. [(k*d) v f] horseshoe (m v c). / m v c: as opposed to fallacy of affirming the consequent, modus tollens (mt, a uniform substitution instance using simple or compound statements of the argument form (if p then q. ~ q. p: valid applications, 1. (r horseshoe p) v s. ~ ( r horseshoe p). Justification: applying the rules of inference justification: refers to the rule of inference that is applied to every validly derived step in a proof: exercises 8b i, 1. ~ (p v q) horseshoe ~ r: 2. ~ s horseshoe ~ r: 1,2, ____ P horseshoe r. ~ s. p v q. r horseshoe s. /q: 5. L horseshoe ( s horseshoe p): 3. Q horseshoe ( r horseshoe s: 4. l, 5.
