Further reading

The adjunction and essential-image facts used in the representation theorem are standard category theory; see Mac Lane [ 1971 ] and Riehl [ 2016 ] . Pointwise and enriched right Kan extensions are developed by Kelly [ 1982 ] . Witsenhausen’s information structures and intrinsic model motivate the separation between information available to a policy and the closed-loop history that policy induces [ Witsenhausen , 1971 , 1975 ] . The foundational numerical treatment of synchronous, partially asynchronous, and totally asynchronous computation is due to Bertsekas and Tsitsiklis [ 1989 ] . Its event-order viewpoint motivates the separation here between an intrinsic causal shape and an external linearization. The interpretation of comparator classes as right-Kan descent along a reference-shape map, and the resulting refinement spectrum, are proposed here as part of UODL.