question.md

Figure sussman-anomaly-figure (page sussman-anomaly-figure) shows a blocks-world problem that is known as the {Sussman anomaly}. The problem was considered anomalous because the noninterleaved planners of the early 1970s could not solve it. Write a definition of the problem and solve it, either by hand or with a planning program. A noninterleaved planner is a planner that, when given two subgoals $G_{1}$ and $G_{2}$, produces either a plan for $G_{1}$ concatenated with a plan for $G_{2}$, or vice versa. Can a noninterleaved planner solve this problem? How, or why not?