Rewriting Logic Specification Research Articles

Automatic generating algorithm of rewriting logic specification for multi-agent system models based on Petri nets

Automatic generating algorithm of rewriting logic specification for multi-agent system models based on Petri nets

Slicing from formal semantics: Chisel—a tool for generic program slicing

We describe Chisel, a tool that synthesizes a program slicer directly from a given algebraic specification of a programming language operational semantics \(\mathcal {S}\). \(\mathcal {S}\) is assumed to be a rewriting logic specification, given in Maude, while the program is a ground term of this specification. Chisel takes \(\mathcal {S}\) and synthesizes language constructs, i.e., instructions, that produce features relevant for slicing, e.g., data dependency. We implement syntheses adjusted to each feature as model checking properties over an abstract representation of \(\mathcal {S}\). The syntheses results are used by a traditional interprocedural slicing algorithm that we parameterize by the synthesized language features. We present the tool on two language paradigms: high-level, imperative and low-level, assembly languages. Computing program slices for these languages allows for extracting traceability properties in standard compilation chains and makes our tool fitting for the validation of embedded system designs. Chisel’s slicing benchmark evaluation is based on benchmarks used in avionics.

Declarative debugging of rewriting logic specifications

Declarative debugging is a semi-automatic technique that starts from an incorrect computation and locates a program fragment responsible for the error by building a tree representing this computation and guiding the user through it to find the error. Membership equational logic (MEL) is an equational logic that in addition to equations allows one to state membership axioms characterizing the elements of a sort. Rewriting logic is a logic of change that extends MEL by adding rewrite rules, which correspond to transitions between states and can be nondeterministic. We propose here a calculus to infer reductions, sort inferences, normal forms, and least sorts with the equational subset of rewriting logic, and rewrites and sets of reachable terms through rules. We use an abbreviation of the proof trees computed with this calculus to build appropriate debugging trees for both wrong (an incorrect result obtained from an initial result) and missing answers (results that are erroneous because they are incomplete), whose adequacy for debugging is proved. Using these trees we have implemented Maude DDebugger, a declarative debugger for Maude, a high-performance system based on rewriting logic. We illustrate its use with an example.

Proof Search for the First-Order Connection Calculus in Maude

This paper develops a rewriting logic specification of the connection method for first-order logic, implemented in Maude. The connection method is a goal-directed proof procedure that requires a careful control over clause copies. The specification separates the inference rule layer from the rule application layer, and implements the latter at Maude's meta-level. This allows us to develop and compare different strategies for proof search.

Equational Abstractions for Reducing the State Space of Rewrite Theories

The combinatorial explosion of state spaces is the biggest problem in applying model checking methods to concurrent systems. In this paper we present a new state-space reduction technique that is tailored to system specifications in Rewriting Logic, a unified semantic framework for concurrency which is based on conditional term rewriting modulo equational theories. The idea is to hide “unimportant” details of the system's behavior (such as internal computations) in the equations, and to represent only “interesting” state changes (such as communication operations) by explicit transitions. We show how this optimization can be implemented by transforming the Rewriting Logic specification, avoiding the construction of the full state space. Moreover we establish the correctness of our technique by proving that the original and the reduced system are weakly bisimilar, and demonstrate its usability by applying it to the concurrent functional programming language Erlang.

An Extensible Module Algebra For Maude

The fact that rewriting logic and Maude are reflective, so that rewriting logic specifications can be manipulated as terms at the metalevel, opens up the possibility of defining an algebra of module composition and transformation operations within the logic. This makes such a module algebra easily modifiable and extensible, enables the implementation of language extensions within Maude, and allows formal reasoning about the module operations themselves. In this paper we discuss in detail the Maude implementation of a specific choice of operations for a module algebra of this type, supporting module operations in the Clear/OBJ tradition as well as the transformation of object-oriented modules into system modules.