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Why Read This Book? - Index of

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16 Chapter 1 Language and Mathematics<br />

Example 1.1.5 Construct a truth table for the statement (p ∧ q) ∨ (¬p ∧¬q).<br />

See Table 1.5.<br />

Solution<br />

p q ¬p ¬q p ∧ q ¬p ∧¬q (p ∧ q) ∨ (¬p ∧¬q)<br />

T T F F T F T<br />

T F F T F F F<br />

F T T F F F F<br />

F F T T F T T<br />

(1.5)<br />

EXERCISE 1.1.6 Use the layout <strong>of</strong> Table 1.6 to construct truth table columns<br />

for p ∧ (q ∨ r) and (p ∧ q) ∨ (p ∧ r).<br />

p q r q ∨ r p ∧ (q ∨ r) p ∧ q p ∧ r (p ∧ q) ∨ (p ∧ r)<br />

T T T<br />

T T F<br />

T F T<br />

T F F<br />

F T T<br />

F T F<br />

F F T<br />

F F F<br />

EXERCISE 1.1.7 Construct truth tables for the following statements.<br />

(a) p ∨ (q ∨ r)<br />

(b) ¬(p ∧ q) ∨ (p ∨ q)<br />

(c) (p ∨ q) ∨ r<br />

(d) ¬p ∨ q<br />

(e) p ∧ (q ∨¬p)<br />

1.1.5 Logical Equivalence<br />

�<br />

(1.6)<br />

There are <strong>of</strong>ten several equivalent ways to say the same thing. We need to address<br />

the situation where two different constructs involving statements should be interpreted<br />

as having the same meaning, or as being logically equivalent. As a trivial

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