Описание тега gf

GF, Grammatical Framework, is a programming language for multilingual grammar applications. It is

• a special-purpose language for grammars, like YACC, Bison, Happy, BNFC, but not restricted to programming languages
• a functional language, like Haskell, Lisp, OCaml, Scheme, SML, but specialized to grammar writing
• a natural language processing framework, like LKB, XLE, Regulus, but based on functional programming and type theory
• a categorial grammar formalism, like ACG, CCG, but different and equipped with different tools
• a logical framework, like Agda, Coq, Isabelle, but equipped with concrete syntax in addition to logic

http://www.grammaticalframework.org/