This is a Haskell program to solve binary puzzles, or binary sudoku like those you can find at binarypuzzle.com.
Prior art exists for solving binary puzzles using code, but not in Haskell that I am aware of. My approach owes a lot to Richard Bird's sudoku solver in Pearls of Functional Algortithim Design and you can read about it in my blog post at charlieharvey.org.uk/page/solving_binary_pussles_with_haskell.