Picat The Planner Module 2

Question 1

Which directive correctly imports the Picat planner module?

Accepted Answer

import planner.

Answer

The correct syntax is `import planner.` placed at the top of the Picat source file.

Question 2

What are the two user-defined predicates that the Picat planner module requires?

Accepted Answer

action/4 and final/1

Answer

The planner requires `action(State, NextState, Action, Cost)` and `final(State)` to be defined by the user.

Question 3

What is the arity of the `action` predicate used in Picat's planner module?

Accepted Answer

4

Answer

`action/4` takes four arguments: the current state, next state, the action term, and its cost.

Question 4

What does the second argument of `plan/2` return after a successful call?

Accepted Answer

A list of action terms constituting the plan

Answer

`plan(State, Plan)` unifies Plan with a list of action terms that lead from State to a final state.

Question 5

In `plan/4`, what does the second argument (Limit) represent?

Accepted Answer

An upper bound on the total resource cost

Answer

`plan(State, Limit, Plan, Cost)` uses Limit as an upper bound on the accumulated action costs, not raw depth.

Picat Practice Test