Description:

Agda is a dependently typed functional programming language: it has
inductive families, which are similar to Haskell's GADTs, but they can
be indexed by values and not just types. It also has parameterized
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.

For Emacs mode install emacs-agda.

If you want to use the command-line program (agda),
then you should also install Agda-executable.