My bachelor's thesis at MIT (under Gerald Sussman) was on "truth maintenance systems" (TMS) --- the problem of maintaining a consistent set of beliefs subject to belief revision. This had been the topic of Jon Doyle's PhD thesis, also under Sussman. My bachelor's thesis introduced a system that later became known as an LTMS (or logic TMS) which took the basic data structure to be an instance of SAT (a set of propositional clauses). An LTMS incrementally maintains closure under unit resolution as "premises" are added and removed.

The bachelor's thesis appeared as a 1978 AI Lab Memo entitled "a three-valued truth maintenance system". However, the more mature reference is a 1980 MIT AI Lab memo An Outlook on Truth Maintenance .

My master's thesis was an extension to include congruence closure (equality reasoning). This became another 1980 MIT AI Lab Memo Reasoning Utility Package User's Manual

Another standard reference is a paper on truth maintenance that was invited to AAAI in 1990.