Procedure for Finding Prime Implicants
1)
Find prime
implicants by finding all permitted (integer power of 2) maximum sized
groups of minterms.
2)
Find essential
prime implicants by identifying those prime implicants that contain at
least one minterm not found in any other prime implicant.
Example
Answer: Z’
Rule
1)
Every variable
in an Σ Π that is a 0 in every square appears complemented in the
final product term.
2)
Every variable
in an Σ Π that is a 1 in every square appear as is in the final
product term.
3)
A 0 in half of
the square a 1 in half of the squares; in which case does not appear at all in
the final term.
Example
Q = f(a, b, c) = Σ(1, 2, 3, 6, 7)

Two prime
implicant {1, 3} {2, 3, 6, 7}

Both are
essential Q = Y + X’Z