fact             1305 magick/morphology.c         order_f = fact(kernel->width-1);
fact             1315 magick/morphology.c               alpha = order_f / ( fact((size_t) v) * fact(kernel->height-v-1) );
fact             1318 magick/morphology.c                 (alpha * order_f / ( fact((size_t) u) * fact(kernel->height-u-1) ));