Question 23
AUTOMATED PLANNING
The domain description of a Blocks World with a single one-armed robot is given below.
PREDICATES
armEmpty The arm is not holding any block, it is empty.holding(X) The arm is holding X.onTable(X) X is on the table.clear(X) X has nothing above it, it is clear.on(X,Y) X is directly placed on Y.
OPERATORS
Pickup(X): pick up X from the table. Preconditions: { armEmpty, clear(X), onTable(X) } Add Effects : { holding(X) } Del Effects : { armEmpty, onTable(X) }
Putdown(X): place X on the table. Preconditions: { holding(X) } Add Effects : { armEmpty, onTable(X) } Del Effects : { holding(X) }Unstack(X,Y): pick up X that is directly sitting on Y. Preconditions: { armEmpty, clear(X), on(X,Y) } Add Effects : { clear(Y), holding(X) } Del Effects : { armempty, on(X,Y) }
Stack(X,Y): place X directly on top of Y. Preconditions: { holding(X), clear(Y) } Add Effects : { armEmpty, on(X,Y) } Del Effects : { holding(X), clear(Y) }Based on the above data, answer the given subquestions.
Which of the following are relevant actions in the goal state?
Putdown(D)
Unstack(D, B)
Unstack(C, A)
Pickup(E)
Pickup(A)
Stack(B, A)
Stack(A , C)