Roger Hui wrote: > You may like 2!1+m instead of 2%~m*1+m . I'd be inclined to leave it in the original form, even though they are obviously equal. These sums of powers forms (as polynomials) are given as elementary examples of induction, and readers are likely to recognize them as such. They are "phrases" (not idioms) in mathematics. The connection with the binomial coefficient is less obvious. If there was a performance hit, I would work at optimization.
Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
