Three Early Formal Approaches to the Verification of Concurrent Programs

Abstract This paper traces a relatively linear sequence of early research approaches to the formal verification concurrent programs. It does so forwards and then backwards in time. After briefly outlining context, key insights from three distinct 1970s are identified (Ashcroft/Manna, Ashcroft (solo) Owicki). The main technical material focuses on specific program taken last published pieces (Susan Owicki’s): her own Findpos example is outlined followed by attempts at verifying same using earlier approaches. Reconsidering prior basis Owicki’s useful illuminates similarities differences between proposals. Along way, observations about interactions researchers (and some “blind spots”) noted.