Recurrences for Quadrilateral High-Order Finite Elements

High order finite element methods (FEM) are well established numerical techniques for solving partial differential equations on complicated domains. In particular, if the unknown solution is smooth, using polynomial basis functions of higher degree speeds up the numerical solution significantly. At the same time, the computations get much more involved and any simplification, such as efficient recurrence relations, are most welcome. Recently, computer algebra algorithms have been applied to improve FEMs in several ways. In this note, we present a symbolic approach to an issue occuring when working with quadrilateral elements.