function BACKTRACKING-SEARCH(csp) returns a solution, or failure
	return BACKTRACK({}, csp)

function BACKTRACK (assignment, csp) returns a solution, or failture
	if assignment is complete then return assignment
	var := SELECT-UNASSIGNED-VARIABLE(csp)
	for each value in ORDER-DOMAIN-VALUES(var, assignment, csp) do
		if value is consistent with assignment then
			add { var = value } to assignment
			inferences := INFERENCE(csp, var, value)
			if inferences ≠ failure then
				add inferences to assignment
				result := BACKTRACK(assignment, csp)
				if result ≠ failure then
					return result
		remove { var = value } and inferences from assignment
	return failure