Figure 6.

The subgoal hierarchies for the three hypotheses. Moving from the top to the bottom hierarchy, bold text represents new subgoals added to the tree above. This has the consequence that Hypotheses 1 is a subset of Hypotheses 2, etc. Goal processing starts at the top and chooses between subgoals until it reaches a terminal branch. Subgoal processing is assumed to persist until either the subgoal is achieved and processing moves up to the parent goal, or the updating process allows switching to a goal at a higher level in the tree. Some subgoals have multiple, self-terminating components in their implementation, and these should be read from left to right.