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Logic: Truth Tables. Constructing a Truth Table. Truth Table. A truth table for a compound statement is a list of the truth or falsity of the statement for every possible combination of truth and falsity of its components.
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Logic: Truth Tables Constructing a Truth Table
Truth Table • A truth table for a compound statement is a list of the truth or falsity of the statement for every possible combination of truth and falsity of its components. • In other words, a truth table helps to show whether a statement is true or false.
Rows • To find the number of rows used in a truth table, take the number 2 raised to the power of the number of variables. • For example, if there was a p statement and a q statement, there would be 2 variables, 2^2 is 4. • If there were three statements, it would be 2^3, or 8 rows.
Columns • The columns under the connectives /\, and \/, stand for the conjunction, and disjunction of the expression on the two sides of that connective.
Use the final column to determine what type of statements it is
Contingency • Some were true, while one was false. • That makes this statement a contingency.
Real life example • In case that was not entirely clear, let’s take a look at an everyday example. • Circuits. There are two different kinds of circuits, a series circuit and a parallel circuit. • When the switch is closed the light will be on. However, with a series circuit, both switches have to be closed and with a parallel circuit only one switch has to be closed for the light to go on.
Conclusion • That concludes the Logic: Truth Tables lesson. • For more information, consult Finite Mathematics by Berresford and Rockett. • Or learn logic online: http://www.earlham.edu/~peters/courses/log/terms2.htm