A computer-parsing system using vectors (lists) to represent natural-language elements, providing a robust, distributed way to score grammaticality of an input string by using as a source material a large corpus of natural-language text. The system uses recombining of asymmetric associations of syntactically similar strings to form the vectors. The system uses equivalence lists for subparts of the string to build equivalence lists for longer strings in an order controlled by the potential parse to be scored. The power of recombination of vector elements in building longer strings provides a means of representing collocational complexity. Grammaticality scoring is based upon the number and similarity of the vector elements.