# Boolean function in terms of K-map

I am working on a Boolean function question. I have produced a truth table out of a 4-variables K-map. How do I state the Boolean functions in canonical form? Must I include both SOP & POS? Also, how do I determine the minimum number of basic logic gates by minimizing the Boolean functions using K-map method?

Minimum gates: yes, minimizing terms using K-Map is a good start ... but it may not minimize the number of gates. For example, through the K-map method you may find $ab + ac + d$ as the minimal SOP, but $a(b+c)+d$ has fewer gates. You wouldn't find this using the K-Map since this is not in SOP or POS.