We present a type inference algorithm for the underlying language and type system of a logic (AL [2]) of Abadi and Leino. We approach the problem by following the techniques used by Palsberg and his coauthors [7, 9] whereby, using a language-based representation of types, we construct an automaton to recognise a least-shape type derivation. To overcome technical problems caused in part by the w...

In a previous paper we have deened a semantic preorder called operational subsumption , which compares terms according to their error generation behaviour. Here we apply this abstract framework to a concrete language, namely the Abadi-Cardelli object calculus. Unlike most semantic studies of objects, which deal with typed equalities and therefore require explicitly typed languages, we start her...

In this paper we give a denotational model for Abadi and Cardelli’s first order object calculus FOb1+×μ (without subtyping) in the category pCpo. The key novelty of our model is its extensive use of recursively defined types, supporting self-application, to model objects. At a technical level, this entails using some sophisticated techniques such as Freyd’s algebraic compactness to guarantee th...

<strong>Empowerment of Sumber Abadi Forest Farmer Groups through Innovation Porang Nursery Techniques.</strong> Farmers Group (FFG) is located in Panglungan Village, Wonosalam District, Jombang Regency, whose area 500-750 m asl and daily temperature 20° C. The conditions socio-economic need to be improved, considering that their livelihoods depend on forest products half the populat...

In this paper we consider rewrite systems that describe the-calculus enriched with recursive and non-recursive local deenitions by generalizing thèexplicit substitutions' used by Abadi, Cardelli, Curien, and L evy 1] to describe sharing in-terms. This leads tòexplicit cyclic substitutions' that can describe the mutual sharing of local recursive deenitions. We demonstrate how this may be used to...

The computational soundness of formal encryption is studied extensively following the work of Abadi and Rogaway[1]. Recent work considers the scenario in which secret sharing is needed, and separately, the scenario when key cycles are present. The novel technique is the use of a co-induction definition of the adversarial knowledge. In this paper, we prove a computational soundness theorem of fo...

In this paper we present a modal logic for describing properties of terms in the object calculus of Abadi and Cardelli [AC96]. The logic is essentially the modal mu-calculus of [Koz83]. The fragment allows us to express the temporal modalities of the logic CTL [BAMP83]. We investigate the connection between the type system Ob1<:μ and the mu-calculus, providing a translation of types into modal ...

Garg and Abadi recently proved that prominent access control logics can be translated in a sound and complete way into modal logic S4. We have previously outlined how normal multimodal logics, including monomodal logics K and S4, can be embedded in simple type theory and we have demonstrated that the higher-order theorem prover LEO-II can automate reasoning in and about them. In this paper we c...

Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward simulations. This formalism is semantically complete: every simulation is a composition of a forward simula...

This paper discusses two methodological approaches for combining concurrent programs written in a modular way. The rst one is based on the composition of traces. It is intuitive and simple but evidences the need for a more abstract approach. The second one meets this need. It composes speciications written in a UNITY-like temporal logic, and rests on Abadi and Lamport's composition principle ((...