Implicit constraints

Explains that implicit constraints may imply infeasibility.

Implicit constraints are implied by operators. For example:

using CP;
int a[1..4];

dvar int x in 1..5;

maximize a[x];

subject to
{
  x==5;
}

makes the model infeasible even though

using CP;
int a[1..4];

dvar int x in 1..5;

subject to
{
  x==5;
}

is feasible.