# CS 1571: Homework 9

## Knowledge Representation for Planning (Chapters 10 and 11): Paper Problems (100 pts)

Assigned: November 18, 2008

Due: November 25, 2008

#### 1. Situation Calculus (50 pts)

Let us consider how we might translate a planning problem using the STRIPS representation, namely (parts of) Figure 11.2 from the text (page 380), into an equivalent situation calculus representation.

(a) What are the fluents and what are the eternals?

(b) Use your answer from part (a) to write a suitable logical description of the initial and goal situations described in Figure 11.2

(c) Write all the possibility, effect, and frame axioms that are needed to capture the same information as the action schema Fly(p,from,to) from Figure 11.2

(d) Write a suitable logical query whose solutions will provide possible paths to the goal situation.

(e) Give one possible path to the goal situation, that you might find using resolution theorem proving (Note: You don't have to do the theorem proving, just show an example solution).

#### 2. Strips (50 pts)

Now let us consider how we might translate the situation calculus representation of the Wumpus World on pages 330-331 into STRIPS.

(a) Write a suitable STRIPS notation description of the initial and goal situations described on page 330.

(b) Write action schemas that are equivalent to the actions Go, Grab and Release as described by the relevant axioms on p. 331.

Grading Criteria: Your answers must use proper syntax for the knowledge representation language (situation calculus for question 1, STRIPS for question 2), and in addition be semantically equivalent after the syntactic translation.