What is Love, a technical approach to find the answer:

Technically i can define love as a real time degree of measuring priority of an individual or a thing in your life.The thing or person you love the most, always have have highest priority in your life.

This is not the complete definition of Love. As we all know Love can also be defined spiritually and in other ways. In-fact, Love can not be completely defined by single of them, it is a broad concept as the domain of love is boundless and so does it's range.

Comparing love with a problem of set, just remember there always exist a null and hopefully a power-set too. Although, their probability of occurrence might be low but they do exist so be aware of the first one of them.

Now this concept of prioritizing on the scale of love helps a lot in solving a lot of questions(mainly decision making situations).You can resolve things using this priority alone.