+`-/ 1 2 3 0 +`+`-/ 1 2 3 6
I call this as being inserted between items on a right to left basis. 1 + 2 - 3 + 4 +`-/ 1 2 3 4 _4 +`-/ 1 2 3 ----- Original Message ----- From: Dan Bron <[email protected]> To: J Programming <[email protected]> Sent: Monday, June 13, 2016 9:04 PM Subject: Re: [Jprogramming] Am I understanding m/y ? Louis wrote: > There was some talk a while ago about the ambiguity of the dictionary about > the direction of gerund insertion. Reading through the first pages of > Iverson's Concrete Math Companion, I stumbled on a snippet of J that dates > back to 2002 and was written by Iverson at the bottom of page 6: > > http://www.jsoftware.com/books/pdf/cmc.pdf > <http://www.jsoftware.com/books/pdf/cmc.pdf> > > According to this source, gerunds do indeed "unroll" from left to right > correctly in the current implementation. I’m also on mobile, so forgive my terse answer and potential misunderstanding of your question, but yes: v0`v1`v2`v3/ y is indeed: … (_8{y) v2 (_7{y) v3 (_6{y) v0 (_5{y) v1 (_4{y) v2 (_3{y) v1 (_2{y) v0 _1{y That is, the insertion of verbs starts at the rightmost (last) elements of y, but the leftmost (first) elements of the gerund G, where G/y . The rationale for this is left as an exercise for a less lazy respondent (though the right-to-left nature of insertion in y should be familiar to veteran J’ers). -Dan ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
