Issues left by ERE

• One of the purposes of Problem Reduction Rules is to reduce the possibility of backtracking, and can do so if it can guarantee independence of events in the environment. However, events in unpredictable environments cannot be so guaranteed, so this purpose of PRRs in such circumstances is generally moot.
• The implementation leaves open the issue of truth maintenance.
• The Utility Problem has yet to be addressed.
• Control between components and the interaction amongst their actions has only recently been explored, with the possibility of negative interaction in existence.
• Managing dependencies between various arenas of knowledge is an open research problem.