The calculation of heat-kernel coefficients with the classical DeWitt
algorithm has been discussed. We present the explicit form of the coefficients
up to h5 in the general case and up to h7min for the minimal parts.
The results are compared with the expressions in other papers. A method to
optimize the usage of memory for working with large expressions on universal
computer algebra systems has been proposed.Comment: 12 pages, LaTeX, no figures. Extended version of contribution to
AIHENP'95, Pisa, April 3-8, 199