CS 2102 Midterm: cs2102_midterm_note_1

• School: University of Virginia
• Department: Computer Science
• Course: CS 2102
• Professor: David Evans

Document Summary

::= means equal by de nition. logically equivalent - one holds if and only if the other does. A valid formula is one which is always true, no matter what truth values its variables may have. A satis able formula is one which can sometimes be true that is, there is some assignment of truth values to its variables that makes it true. Every propositional formula is equivalent to both a disjunctive normal form and a conjunctive normal form. !2 b. x a x b x a b by de nition of . A and b do not include exactly same elements in sets. So long as b is not the compliment of a, b a. Therefore a b will result in a set of element such that x is an element of s such that x a x b.