200px|thumb|In this image, the universal set U (the entire rectangle) is dichotomized into the two sets A (in pink) and its complement Ac (in grey). A dichotomy () is a partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be jointly exhaustive: everything must belong to one part or the other, and mutually exclusive: nothing can belong simultaneously to both parts.
200px|thumb|In this image, the universal set U (the entire rectangle) is dichotomized into the two sets A (in pink) and its complement Ac (in grey). A dichotomy () is a partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be jointly exhaustive: everything must belong to one part or the other, and mutually exclusive: nothing can belong simultaneously to both parts.
If there is a concept A, and it is split into parts B and not-B, then the parts form a dichotomy: they are mutually exclusive, since no part of B is contained in not-B and vice versa, and they are jointly exhaustive, since they cover all of A, and together again give A.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).