Dichotomy

A dichotomy (/daɪˈkɒtəmi/) is a partition of a whole (or a set) into two parts (subsets).

Such a partition is also frequently called a bipartition.

In logic, the partitions are opposites if there exists a proposition such that it holds over one and not the other.

The discretization error inherent in dichotomization is temporarily ignored for modeling purposes.

The term dichotomy is from the Greek Greek: διχοτομία dichotomía "dividing in two" from δίχα dícha "in two, asunder" and τομή tomḗ "a cutting, incision".

In this image, the universal set U (the entire rectangle) is dichotomized into the two sets A (in pink) and its complement A c (in grey).