COGS 100 Lecture Notes - Lecture 12: Modus Ponens, Propositional Calculus, Problem Solving

• School: Queen's University
• Department: Cognitive Science
• Course: COGS 100
• Professor: Farhana Zulkernine

Document Summary

Both alan and betty will go to the concert, or carol will go. Alan will not go, or betty will not go. Cogs100: introduction to cognitive science - lecture 12: logic and probability. Notice that there is no modus ponens in the first statement (if p then q: select symbols. D dave will go: convert to logic expressions (i). (a b) c (ii). For problem 1, we want to prove c. so the expression should be p c, p/c (modus ponens) We can transform the logic expressions as follows: (i) (a b) c = (a b) c (ii) a b = (a b) (a b) c, (a b)/c - (modus ponens) For problem 2, we simply use the value of c derived above with (iii) and create a chain of inferences. Predicate logic (predicate calculus) provides much greater expressive power than propositional logic. A sentence divided into a subject and predicate to increase expressive power.