We consider commutative Frobenius algebras in braided strict monoidal categories in the study of the circuits and communicating systems which occur in Computer Science, including circuits in which the wires are tangled. We indicate also some possible novel geometric interest in such algebras. For example, we show how Armstrong's description of knot colourings and knot groups fit into this context.
Keywords: circuit diagram, braided monoidal category, tangle algebra
2010 MSC: 18B20, 18D10, 68Q05, 68Q85
Theory and Applications of Categories, Vol. 26, 2012, No. 27, pp 743-767.