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Logical Expressions and Negations in Clinical Study Context

snhu MODULE ONE PROBLEM SET This document is proprietary to Southern New Hampshire University. It and the problems within may not be posted on any non-SNHU website. Your Name Here 1 snhu Directions: Type your solutions into this document and be sure to show all steps for arriving at your solution. Just giving a final number may not receive full credit. PROBLEM 1 In the following question, the domain of discourse is a set of male patients in a clinical study. Define the following predicates: · P(x) : x was given the placebo · D(x) : x was given the medication · M(x) : « had migraines Translate each of the following statements into a logical expression. Then negate the expression by adding a negation operation to the beginning of the expression. Apply De Morgan's law until each negation operation applies directly to a predicate and then translate the logical expression back into English. Sample question: Some patient was given the placebo and the medication. . Ex (P(x) A D(x)) . Negation: - 3x (P(x) \ D(x)) . Applying De Morgan's law: Vx (-P(x) V -D(x)) · English: Every patient was either not given the placebo or not given the medication (or both). (a) Every patient was given the snhu medication or the placebo or both. Logical Expression: Vx(D(x) V P(x) V(P(x) AQ(x)) Negation: - Vx(D(x) V P(x)V(P(x) AQ(x)) 3x(-D(x) A-Q(x) A (-D(x) V-Q(x))) De Morgan's Law: 3x(-(D(x) A-P(x)) There is at least one patient who was not give the medication, placebo, or both. (b) Every patient who took the placebo had migraines. (Hint: you will need to apply the conditional identity, p -> q = p V q.) Logical Expression: Vx(P(x) -> M(x)) Negation: - Vx(P(x) -> M(x)) Conditional Identity: - Vx(P(x) VQ(x)) Negation: 3x-(-P(x) V Q(x)) De Morgrgan's Law: 3x(P(x) A-Q(x)) English: At least one patient took the placebo and did not have migraines. (c) There is a patient who had migraines and was given the placebo. Logical Expresvsion: 3x(M(x) \P(x)) Negation: - 3x(M(x) \P(x)) De Morgan's Law: Vx(-M(x) V P(x)) English: Every patient did not take the placebo or did not have migraines.