Written Assignment - Logic and Planning

Max points:
The assignment should be submitted via Canvas.

Instructions


Task 1 (CSE 4308: 10 Points; CSE 5360: 10 points)

Does a unifier exist for these pairs of predicates. If they do, give the unifier

i. Taller(x, John); Taller(Bob, y)
ii. Taller(y, Mother(x)); Taller(Bob, Mother(Bob))
iii. Taller(Sam, Mary); Shorter(x, Sam)
iv. Shorter(x, Bob); Shorter(y, z)
v. Shorter(Bob, John); Shorter(x, Mary)


Task 2 (CSE 4308: 18 Points (+5 Points EC); CSE 5360: 18 points (+5 Points EC))

Two adults and two children are on the left side of the river. They all want to cross to the right side of the river. However, the only means of transportation they can use is a boat (also initially on the left bank) which can carry either just one adult or one adult and one child or just one child or two children from one bank to the other bank. Any adult or child can operate the boat, but the boat cannot be operated without having at least one person on the boat. The goal is to come up with a plan for moving everyone from the left side to the right side using multiple boat trips.

Describe the initial state and the goal, using PDDL. Define appropriate actions for this planning problem, in the PDDL language. For each action, provide a name, arguments, preconditions, and effects.

Extra Credit (5 pts): Also, give a complete plan (using the actions described) for getting from the start to the goal state


Task 3 (CSE 4308: 10 Points; CSE 5360: 10 points)

Suppose that we are using PDDL to describe facts and actions in a certain world called JUNGLE. In the JUNGLE world there are 3 predicates, each predicate takes at most 4 arguments, and there are 5 constants. Give a reasonably tight bound on the number of unique states in the JUNGLE world. Justify your answer.


Task 4 (CSE 4308: 12 Points; CSE 5360: 12 points)

Consider the problem in Task 2. Let us say that, if there is only one person in the boat, the boat can be blown off course and end up back on the side it originally started from. How would you modify the actions you described in Task 2 to account for this if you were going to try and handle this scenario by
In both cases, show what the modifications are (If no modification is necessary, Justify).