Sylvia is a logical puzzle game, based on a field of mathematics called lambda calculus. You start with a library of functions, and combine them together in various ways.
See the wiki for documentation.
git clone git://github.com/lfairy/sylvia
cd sylvia
cabal configure
cabal install --only-dependencies
cabal build
dist/build/sylvia '\ 0 0'
See Building from source for more detailed instructions, and Examples for examples, of course.