Finds solutions to any knights-n-knaves puzzle using Haskell.
A knight always tells the truth and a knave always lies.
Assuming you have Haskell's stack and ghc installed, you can clone this repository and run stack build and then stack exec knights-n-knaves-exe. Here is an example session:
/path/to/repo $ stack exec knights-n-knaves-exe
Gwen says (Art is a knight) iff (Lance is a knight)
Art says Gwen is a knave
solve
Solution 1:
Knights: Gwen
Knaves: Art, Lance
Solution 2:
Knights: Art
Knaves: Gwen, Lance
quit
/path/to/repo $
Currently, the logical connectives not, and, or, if, and iff are supported.