I know a kid named Greg with four fingers on one hand, and "pi" on the other, i.e., three plus just the tip of a fourth. Coincidentally, if you start Gregory's series for 4 arctan(1) one term prematurely, block([fancy_display:false], intosum(4*sum((-1)^k/(2*k+1),k,-1,inf)),print(%%=closedform(%%))) inf ==== k \ 4 (- 1) > -------- = %pi + 4 . / 2 k + 1 ==== k = -1 Greg could become a regular J. von Neumann if he learns to sum infinite series by counting on his fingers. --rwg