Formal Basis of a Language Universal

Abstract Steedman (2020) proposes as a formal universal of natural language grammar that grammatical permutations the kind have given rise to transformational rules are limited class known mathematicians and computer scientists “separable” permutations. This is exactly can be expressed in combinatory categorial grammars (CCGs). The excluded non-separable do fact seem absent number studies crosslinguistic variation word order nominal verbal constructions. separable grows n lexical elements construction Large Schröder Number Sn−1. Because much more slowly than n! all permutations, this generalization also considerable practical interest for computational applications such parsing machine translation. present article examines mathematical origins restriction, reason it captured CCG without imposition any further constraints.