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Discrete Mathematics University of Kentucky CS 275 Spring ... - MGNet

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Definition: An implicant is sum term or product term <strong>of</strong> one or more minterms<br />

in a sum <strong>of</strong> products. A prime implicant <strong>of</strong> a function is an implicant that cannot<br />

be covered by a more reduced (i.e., one with fewer literals) implicant.<br />

Note: Suppose f is a Boolean function and P is a product term. Then P is an<br />

implicant <strong>of</strong> f if f takes the value 1 whenever P takes the value 1. This is<br />

sometimes written as P ; f in the natural ordering <strong>of</strong> the Boolean algebra.<br />

Quine-McCluskey: This algorithm has two steps:<br />

1. Find all prime implicants <strong>of</strong> the function.<br />

2. Use those prime implicants in a prime implicant chart to find the essential<br />

prime implicants <strong>of</strong> the function as well as other prime implicants that are<br />

necessary to cover the function.<br />

The algorithm constructs a table and then simplifies the table. The method leads<br />

to computer implementations for large numbers <strong>of</strong> variables. Use high quality<br />

s<strong>of</strong>tware if you use the Quine-McCluskey approach.<br />

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