Open Graphs and Computational Reasoning

Lucas Dixon
(University of Edinburgh)
Ross Duncan
(University of Oxford)
Aleks Kissinger
(University of Oxford)

We present a form of algebraic reasoning for computational objects which are expressed as graphs. Edges describe the flow of data between primitive operations which are represented by vertices. These graphs have an interface made of half-edges (edges which are drawn with an unconnected end) and enjoy rich compositional principles by connecting graphs along these half-edges. In particular, this allows equations and rewrite rules to be specified between graphs. Particular computational models can then be encoded as an axiomatic set of such rules. Further rules can be derived graphically and rewriting can be used to simulate the dynamics of a computational system, e.g. evaluating a program on an input. Examples of models which can be formalised in this way include traditional electronic circuits as well as recent categorical accounts of quantum information.

In S. Barry Cooper, Prakash Panangaden and Elham Kashefi: Proceedings Sixth Workshop on Developments in Computational Models: Causality, Computation, and Physics (DCM 2010), Edinburgh, Scotland, 9-10th July 2010, Electronic Proceedings in Theoretical Computer Science 26, pp. 169–180.
Published: 9th June 2010.

ArXived at: http://dx.doi.org/10.4204/EPTCS.26.16 bibtex PDF

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