Haskell Sudoku Using AC-3 algorithm to solve Constraint satisfaction problems CSP's. A sudoku is a classic example of a CSP. Techniques Forward checking Minimum Remaining Values Most Constraining Value Least Constraining Value AC3 References https://en.wikipedia.org/wiki/Constraint_satisfaction_problem https://en.wikipedia.org/wiki/AC-3_algorithm https://en.wikipedia.org/wiki/Sudoku