Denotational semantics for Abadi and Leino's logic of objects

Abadi-Leino Logic is a Hoare-calculus style logic for a simple imperative and object-based language where every object comes with its own method suite. Consequently, methods need to reside in the store (rdquohigher-order storerdquo). We present a new soundness proof for this logic using a denotational semantics where object specifications are recursive predicates on the domain of objects. Our semantics reveals which of the limitations of Abadi and Leinorsquos logic are deliberate design decisions and which follow from the use of higher-order store. We discuss the implications for the development of other, more expressive, program logics.