In the subroutines that solve Helmholtz problems in two dimensions ( HIBEM2, HEBEM2 and HMBEM2) the boundaries must be represented in the form illustrated in figure below. In order that the normal to the boundary points outward rather than inward, the two nodes that define each element must be listed in the clockwise direction around the boundary. The programs HIBEM2_T, HEBEM2_T and HMBEM2_T each solve Helmholtz problems in which the boundary under consideration is that of a square of side 0.1. The boundary is represented by 32 uniform panels and also has 32 vertices, as illustrated in the square figure below.