Question: Consider the following problem: A patient arrives at the doctor's office with symptoms that could have been caused either by dehydration or by disease D (but not both). There are two possible actions: Drink, which unconditionally cures dehydration, and Medicate, which cures disease D, but has an undesirable side-effect if taken when the patient is dehydrated. Write the problem description in PDDL, and dl~agranl a sensorless plan that solves the problem, enumerating all relevant possible worlds.