32,473 research outputs found
Fifty years of Hoare's Logic
We present a history of Hoare's logic.Comment: 79 pages. To appear in Formal Aspects of Computin
A Refinement Calculus for Logic Programs
Existing refinement calculi provide frameworks for the stepwise development
of imperative programs from specifications. This paper presents a refinement
calculus for deriving logic programs. The calculus contains a wide-spectrum
logic programming language, including executable constructs such as sequential
conjunction, disjunction, and existential quantification, as well as
specification constructs such as general predicates, assumptions and universal
quantification. A declarative semantics is defined for this wide-spectrum
language based on executions. Executions are partial functions from states to
states, where a state is represented as a set of bindings. The semantics is
used to define the meaning of programs and specifications, including parameters
and recursion. To complete the calculus, a notion of correctness-preserving
refinement over programs in the wide-spectrum language is defined and
refinement laws for developing programs are introduced. The refinement calculus
is illustrated using example derivations and prototype tool support is
discussed.Comment: 36 pages, 3 figures. To be published in Theory and Practice of Logic
Programming (TPLP
A framework for deadlock detection in core ABS
We present a framework for statically detecting deadlocks in a concurrent
object-oriented language with asynchronous method calls and cooperative
scheduling of method activations. Since this language features recursion and
dynamic resource creation, deadlock detection is extremely complex and
state-of-the-art solutions either give imprecise answers or do not scale. In
order to augment precision and scalability we propose a modular framework that
allows several techniques to be combined. The basic component of the framework
is a front-end inference algorithm that extracts abstract behavioural
descriptions of methods, called contracts, which retain resource dependency
information. This component is integrated with a number of possible different
back-ends that analyse contracts and derive deadlock information. As a
proof-of-concept, we discuss two such back-ends: (i) an evaluator that computes
a fixpoint semantics and (ii) an evaluator using abstract model checking.Comment: Software and Systems Modeling, Springer Verlag, 201
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