6. Suppose you have a STRIPS representation for actions a1 and a2, and you want to define the STRIPS representation for the composite action a1; a2, which means that you do a1 then do a2.

(a) What are the effects for this composite action?

(b) When is the composite action impossible? (That is, when is it impossible for a2 to be immediately after a1?)

(c) Assuming the action is not impossible, what are the preconditions for this composite action?

(d) Using the delivery robot domain of Example 6.1, give the STRIPS representation for the composite action puc; mc.

(e) Give the STRIPS representation for the composite action puc; mc; dc made up of three primitive actions.

(f) Give the STRIPS representation for the composite action mcc; puc; mc; dc made up of four primitive actions.