# Keep in mind that whenever a proposition represented

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Unformatted text preview: P ¬p p ∨¬p p ∧¬p T F T F F T T F Logically Equivalent ༉  ༉  ༉  ༉  Two compound propositions r and s are logically equivalent if r↔s is a tautology. Denoted by r⇔s or as r≡s where r and s are compound propositions. In other words, two compound propositions r and s are equivalent if and only if the columns in a truth table giving their truth values agree. This truth table show r: ¬p ∨ q is equivalent to s: p → q. p q ¬p ¬p ∨ q p→ q T T F T T T F F F F F T T T T F F T T T De Morgan’s Laws Augustus De Morgan 1806- 1871 This truth table shows that De Morgan’s Second Law holds. p q ¬p ¬q (p∨q) ¬(p∨q) ¬p∧¬q T T F F T F F T F F T T F F F T T F T F F F F T T F T T Key Logical Equivalences ༉  Identity Laws: , ༉  Domination Laws: , ༉  Idempotent laws: , ༉  Double Negation...
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## This document was uploaded on 02/27/2014 for the course CS 215 at SIU Carbondale.

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