"In The indisputable existence of Santa Claus, mathematicians Hannah Fry and Thomas Oléron Evans take readers on a festive journey through the pitfalls of a traditional holiday season. Lighthearted and diverting, and brimming with Christmassy diagrams, sketches and graphs, equations, Markov chains, and matrices, The indisputable existence of Santa Claus brightens up the bleak midwinter with stockingsful of mathematical marvels. Math has never been merrier."--Back cover.