e/Implicit and explicit constraints

Information
has gloss	eng: A combinatorial problem is defined to be one of assigning discrete numerical values to some finite set of variables x, in such a way as to satisfy a set of constraints and minimise some objective function f(x). A large range of flexibility is permitted in both the constraint set and the objective function. The constraints of the combinatorial problem shall be designated as being either implicit or explicit. Implicit constraints are constraints that will be satisfied by the manner in which the branch-and-bound algorithm is constructed. In the resource constrained project scheduling problem, the precedence constraints are an example of implicit constraints: these constraints can easily be satisfied by a branch-and-bound procedure by applying PERT/CPM-like temporal assignments. Explicit constraints, however, are defined to be constraints that will require procedures for recognition as an integral part of the branch-and-bound algorithm.
lexicalization	eng: Implicit and explicit constraints
instance of	c/Variables