Abstract
By combining the displacements and the Airy stress vector into a six-dimensional vector, one ensures that the equations of both compatibility and equilibrium are fulfilled. The same stresses are obtained from both only if a consistency condition is obeyed, which for angularly inhomogeneous media has the form of Schrödinger's equation in the Dirac representation. Accordingly all solutions for dislocations and stress intensities at wedges and cracks are found in terms of ordered matrix exponentials.