Mathematical linguistics is concerned with the study of mathematical properties of natural languages and linguistic theories. Since the mathematical properties of interest to mathematical linguists are usually from theoretical computer science (complexity classes, language hierarchies, formal learnability), mathematical linguistics can be considered as an area of theoretical computational linguistics. However, since statistical methods are rarely used in mathematical linguistics, its relationship to current practices in computational linguistics is somewhat limited. While the introduction of logic in linguistic research has originally come from semantics, this line of work did not really use sophisticated meta-results.