Electronic Journal of Differential Equations,
Vol. 1996(1996), No. 11, pp. 1-9.

Title: On the Regularity of Elliptic Differential Equations
       Using Symmetry Techniques and Suitable Discrete Spaces

Author: Christoph Pflaum (Univ. of Wurzburg, Am Hubland, Germany)

Abstract: We present an elementary and short proof for regularity of 
second order elliptic differential equations with homogeneous Dirichlet
boundary conditions. The proof uses a discrete function space with 
piecewise multilinear functions and symmetry techniques on the unit cube.

Submitted July 25, 1996. Published November 22, 1996.
Math Subject Classification: 65D10.
Key Words: regularity of elliptic differential equations.