Exercise 10.17 [strips-translation-exercise]

Consider how to translate a set of action schemas into the successor-state axioms of situation calculus.

  1. Consider the schema for ${Fly}(p,{from},{to})$. Write a logical definition for the predicate ${Poss}({Fly}(p,{from},{to}),s)$, which is true if the preconditions for ${Fly}(p,{from},{to})$ are satisfied in situation $s$.

  2. Next, assuming that ${Fly}(p,{from},{to})$ is the only action schema available to the agent, write down a successor-state axiom for ${At}(p,x,s)$ that captures the same information as the action schema.

  3. Now suppose there is an additional method of travel: ${Teleport}(p,{from},{to})$. It has the additional precondition $\lnot {Warped}(p)$ and the additional effect ${Warped}(p)$. Explain how the situation calculus knowledge base must be modified.

  4. Finally, develop a general and precisely specified procedure for carrying out the translation from a set of action schemas to a set of successor-state axioms.

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