Automatically Enhancing Constraint Model Instances during Tailoring

Tailoring solver-independent constraint instances to target solvers is an important component of automated constraint modelling. We augment the tailoring process by a set of enhancement techniques of which many are successfully established in related fields, such as common subexpression elimination. Our aim is to apply these techniques in an efficient fashion, since we tailor instance-wise, and not whole problem classes. We integrate automated enhancement into the tailoring procedure, which creates a novel setup with great potential, as our empirical analysis confirms: impressive speedups, additional propagation and instance reduction, all for investing little computational effort.