function OrderedCollection() {
  this.elms = new Array();
}
A JavaScript implementation of the DeltaBlue constraint-solving
algorithm, as described in:

"The DeltaBlue Algorithm: An Incremental Constraint Hierarchy Solver"
  Bjorn N. Freeman-Benson and John Maloney
  January 1990 Communications of the ACM,
  also available as University of Washington TR 89-08-06.

Beware: this benchmark is written in a grotesque style where
the constraint model is built by side-effects from constructors.
I've kept it this way to avoid deviating too much from the original
implementation.