Unary constraints on interval variables

CP Optimizer provides constraints for modeling restrictions that an interval cannot start, cannot end or cannot overlap a set of fixed dates.

Let a_underscore denote a fixed interval and F an integer stepwise function.

  • Forbidden start. The constraint forbidStart(a_underscore, F), states that whenever the interval is present, it cannot start at a value t where F(t) = 0.

  • Forbidden end. The constraint forbidEnd(a_underscore, F), states that whenever the interval is present, it cannot end at a value t where F(t − 1) = 0.

  • Forbidden extent. The constraint forbidExtent(a_underscore, F), states that whenever the interval is present, it cannot overlap a point t where F(t) = 0.

More formally:

unary_con1

For syntax and examples of these constraints, see forbidEnd, forbidExtent, and forbidStart in the OPL Language Quick Reference. Note that none of these constraints can be used in meta-constraints.