 Lyon 2012 sketches a more general theory of mathematical explanations of scientific facts. Starting from the, by now, standard stock of examples discussed in the literature on mathematical explanations of scientific facts (the bees, the cicadas, the sunflower seeds, the bridges of Königsberg, the Kirkwood gaps, the Plateau soap film, etc.), Lyon thinks that they share important properties that can be captured through a distinction already available in the literature on explanation in general philosophy of science. The distinction is that formulated by Jackson and Pettit (1990) between process explanations and program explanations. Lyon’s observation is that in all the standard examples of mathematical explanations listed above there are, in addition to the mathematical explanations, alternative explanations that are causal. Such alternative explanations work at a level of granularity (indicating all the spatio-temporal coordinates, forces acting on the bodies etc.) that is not present in the mathematical explanations. Following the lead of Jackson and Pettit, Lyon calls the former process explanations and the latter program explanation: