--1 The Mathematics API to the Resource Grammar -- This grammar is a collection of the different modules. -- It differs from $Lang$ in two main ways: -- - the combinations in Noun, Verb, Adjective, Adverb, Sentence are not included -- - instead, Symbol and Predication are used -- -- -- In practice, the most important difference is that only present-tense sentences -- are included, and that symbolic expressions are recognized as NPs. abstract Mathematical = Noun - [ComplN2], --- to avoid ambiguity -- Verb, Adjective, Adverb, Numeral, -- Sentence, Question, Relative, Conjunction, Phrase, Text, Idiom, Structural, Symbol, Predication, Lexicon ** {} ;