This is very abstract, but I believe that since both input and output are very close in program space compared to the total size of PS, the heuristics to map be

This is very abstract, but I believe that since both input and output are very close in program space compared to the total size of PS, the heuristics to map between them are going to be of a manageable size. This is based on an intuition about a single source for all activity in this universe.