1. One or more computer-readable storage media comprising computer-executable instructions to perform a method of facilitating access to a resource, the method comprising: creating a first answer set that comprises a first assertion, a first variable, and a first constraint that have been chosen, said first answer set satisfying one or more conditions comprising: that a first set of assertions that comprises or is derived from said first answer set will, when presented to a guard that controls access to the resource, cause said guard to find that a query evaluates to true under a policy implemented by said guard; creating a second answer set that comprises a second assertion, a second variable, and a second constraint that have been chosen, said second answer set satisfying one or more conditions comprising: that a second set of assertions that comprises or is derived from said second answer set will, when presented to said guard, cause said guard to find that said query evaluates to true under said policy; determining that said first answer set is not subsumed by said second answer set; and providing a solution that comprises said first answer set.