CAS PH 160 Lecture Notes - Lecture 6: Deductive Reasoning
Document Summary
Propositional logic (truth-functional logic): the branch of deductive reasoning that deals with the logical relationships among statements; symbols used to represent and clarify these relationships. Connectives: symbols used to express an argument: variables: letters, symbols for the logical connectives that indicate relationships b/w statements. Simple statement: doesn"t contain any other statements as constituents. For a disjunction to be true, only one of the disjuncts must be true. Inclusive sense: p v q = p or q or both. Exclusive sense: p v q = p or q, not both. Use inclusive sense (unless stated: negation (~p): denial of a statement; when ~ appears in front of a statement, it indicates the reversal of the statement true statement becomes false and false statement becomes true. The truth-table test of validity is based on an elementary fact: it"s impossible for a valid argument to have true premises and a false conclusion.
