dependently typed functional programming language

 Agda is a dependently typed functional programming language: It has inductive
 families, which are like Haskell's GADTs, but they can be indexed by values and
 not just types. It also has parameterised modules, mixfix operators, Unicode
 characters, and an interactive Emacs interface (the type checker can assist in
 the development of your code).
 .
 Agda is also a proof assistant: It is an interactive system for writing and
 checking proofs. Agda is based on intuitionistic type theory, a foundational
 system for constructive mathematics developed by the Swedish logician Per
 Martin-Löf. It has many similarities with other proof assistants based on
 dependent types, such as Coq, Epigram and NuPRL.
 .
 This is a meta package which provides Agda's emacs mode, executable, standard
 library and its documentation.