Planning (microworld search)

Descriptions corresponding to nodes in a search space can vary in complexity. In the case of simple, path-finding search, the descriptions we used were atomic; that is to say they were just single words labeling a given location, e.g. “old_steine”. In the case of the search space for the water jugs problem, the descriptions we used were list structures with two components, each component identifying the amount of liquid in one of the two jugs. In the case of the search space for the 8-puzzle, the descriptions used were list structures with nine components, e.g. [1 2 3 4 5 6 7 8 hole]. When considering sets of goals as a states in the previous chapter, each state could be made up of some arbitrary number of such goals. In principle, descriptions (i.e. nodes) can be as complex as we like. Provided the successor function can be computed, the search process can be applied in the usual way.