< quote href = http://www.jsoftware.com/help/jforc/loopless_code_i_verbs_have_r.htm#_Toc141157987
consider the new verb monad +/, which creates the total of the items of its operand (just think of it as 'monad SumItems'): +/ 1 2 3 6 The result was 1 + 2 + 3, as expected. </ quote> To be honest, it would be nice if this result were fleshed out because all the prior examples in this section were based on operands of rank-2. This rank-1 example can be tricky to a beginner because the items of a 1-cell are not arrays, but atoms. Here is my fleshing out of this example: +/ i. 3 The verb rank is 0 and the noun rank is 1, therefore, r is 1 and so we will be applying the verb to 1-cells. The frame f is empty. Think of the operand as an empty array of 1-cells [??? sounds weird] So the operand is a single 1-cell: 0 1 2 It is not an array of anything in this case. The verb is applied to each cell, and we only have a single 1-cell: +/ 0 1 2 Since +/ creates a total of the _items_ of it operand, we must find the _items_ of our operand. The items of a 1-cell are 0-cells. So the members of the 1-cell are our _items_. And +/ will create the total of them, yielding 3 I am thankful for for Figure 1 on this page: http://www.jsoftware.com/help/jforc/loopless_code_i_verbs_have_r.htm#_Toc141157986 because I simply imitated the step-by-step thought process there to come up with the fleshing out that I attempted above. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
