3.21 Implement a constraint satisfaction system as follows:

a. Define a datatype for CSPs with finite, discrete domains. You will need to find a way to represent domains and constraints.

b. Implement operators that assign values to variables, where the variables are assigned in a fixed order at each level of the tree.

c. Implement a goal test that checks a complete state for satisfaction of all the constraints.

d. Implement backtracking by modifying DEPTH-FIRST-SEARCH.

e. Add forward checking to your backtracking algorithm.

f. Run the three algorithms on some sample problems and compare their performance