Account for special features on the sharp edges in the infinite double equation set truncation for diffraction problems

The truncation method application for the infinite double set of the boundary equations is illustrated on an example of the E- and H-polarized wave diffraction on an one-dimensional plane reflection grating containing two grooves on the period. The truncation method takes account for the Meixner’s conditions on the edges of any coordinate structure. It does not demand information about the exact solution asymptotics near the edges.