I didn't think that the symbolic processor would calc a numeric result for an infinite sum. In MCD11 symbolics returns only the same original sum regardelss of the float value; doesn't attempt an evaluation. I tried the symbolic sum as you show in MCD15 and in Prime2, with your result in both cases. However, if the float limit is 20 or higher, then the symbolic answer is "undefined," in both versions, leading me to think that "19" did not appear in your evaluation by coincidence. Any idea why the boundary exists or what may cause it?
Lou
