Question 21: AUTOMATED PLANNING\ The domain description of a Blocks W…

1armEmpty        The arm is not holding any block, it is empty.
2holding(X)      The arm is holding X.
3onTable(X)      X is on the table.
4clear(X)        X has nothing above it, it is clear.
5on(X,Y)         X is directly placed on Y.

1Pickup(X): pick up X from the table.
2     Preconditions: { armEmpty, clear(X), onTable(X) }
3     Add Effects  : { holding(X) }
4     Del Effects  : { armEmpty, onTable(X) }
5
6Putdown(X): place X on the table.
7     Preconditions: { holding(X) }
8     Add Effects  : { armEmpty, onTable(X) }
9     Del Effects  : { holding(X) }
10
11Unstack(X,Y): pick up X that is directly sitting on Y.
12     Preconditions: { armEmpty, clear(X), on(X,Y) }
13     Add Effects  : { clear(Y), holding(X) }
14     Del Effects  : { armempty, on(X,Y) }
15
16Stack(X,Y): place X directly on top of Y.
17     Preconditions: { holding(X), clear(Y) }
18     Add Effects  : { armEmpty, on(X,Y) }
19     Del Effects  : { holding(X), clear(Y) }