A Query Language Based on Term Matching and Rewriting

Recent years have seen the emergence of a data-centric approach to business process modelling as an attractive alternative to the dominant task-centric one. This new paradigm requires new tools for effective specification, simulation and validation of data-centric models. In particular, such tools must include support for expressive query and database update languages. Rewriting logic was proposed (and successfully used) as a generic framework for the specification of dynamic systems. However, though relational and other data models can be easily simulated, rewriting systems lack the direct support for first-order queries. In this paper we describe a novel condition and query language (at least as expressive as relational algebra), implemented in the term rewriting language Maude, together with a simple framework for relational transition system specification and simulation. The language is designed to be easy to implement on the top of a conditional rewriting system. Its most interesting feature is that it avoids all problems with variable binding. It works with models founded both on sets and multisets, and the language has linear-like facilities to refer to multiplicities of facts (in the case of multiset-founded models). As an example of the use of our language and simulation framework we reproduce some specifications of business processes from the literature. We also compare several methods for choosing the next action and its input during simulation.

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Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).