http://www.jsoftware.com/books/pdf/cmc.pdf chapter 5, page 44, says
The binomial theorem expresses a power of a sum (that is, (x+y)^t) as an equivalent weighted sum of products of ascending powers of x and descending powers of y: x=: 3 [ y=: 5 [ t=: 4 [. Ei=: i.@>: I didn't understand [. , nor did the interpreter. |spelling error | x=: 3 [ y=: 5 [ t=: 4 [. Ei=: i.@>: | ^ I guessed that is was supposed to say x=: 3 [ y=: 5 [ t=: 4 [ Ei=: i.@>: but that doesn't work either: x 3 [ (5 [ (4 [ (i.@>:))) y 5 [ (4 [ (i.@>:)) t 4 [ (i.@>:) Ei i.@>: - Bo ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
