MODR 1711 Lecture Notes - Lecture 17: Propositional Calculus
13 Apr 2018
School
Department
Course
Professor
Document Summary
In propositional logic we often encounter compound sentences, i. e. , sentences made up of many different connectives and more than two sentence letters. With conditional and negation symbols it is important to know what the order of operations is. For example, ~pvq is very different from ~(pvq) we use parentheses to indicate this difference. Likewise, p (q p) is very different from (p q) p. Parentheses indicate what the main connective is by marking off compound components. We can use different sorts of parentheses to make clear which bracket matches which: > means it"s possible to indicate a possible truth value for that sentence: a useful tool to help to identify the main connective is called a grammatical tree. In constructing a grammatical tree we simply break up the compound into its smaller components one by one. We start at bottom and work our way up. Practice with grammatical trees (check your written notes: 1.
