Decision variables
Decision variables represent the unknown information in a constraint programming problem.
Decision variables represent the unknown information in a problem. Decision variables differ from standard programming variables in that they have domains of possible values and may have constraints placed on the allowed combinations of theses values. For this reason, decision variables are also known as constrained variables. In this example, the decision variables are x and y.
Each decision variable has a domain of possible values. In this example, the domain of decision variable x is [5..12], or all integers from 5 to 12. The domain of decision variable y is [2..17], or all integers from 2 to 17.
In CP Optimizer and Concert Technology, square brackets denote the domain of decision variables. For example, [5 12] denotes a domain as a set consisting of precisely two integers, 5 and 12. In contrast, [5..12] denotes a domain as a range of integers, that is, the interval of integers from 5 to 12, so it consists of 5, 6, 7, 8, 9, 10, 11 and 12.