> On 3 May 2014 14:22, Alex Giannakopoulos <[email protected]> wrote: >> OK, but can't see which part of the docs clarifies that.
Alex, the dictionary link that R.E. Boss shared, http://www.jsoftware.com/help/dictionary/d630n.htm, concisely documents that behavior. I agree it's somewhat confusing. It's also covered in the new vocabulary more explicitly: http://www.jsoftware.com/jwiki/Vocabulary/ampm One of the keys to understanding this is being able to recognize what x,m,v,u,y are. It probably belongs on the NewVoc glossary page, http://www.jsoftware.com/jwiki/Vocabulary/AbsolutelyEssentialTerms One of the better descriptions of x,m,v,u,y,etc I've seen can be found in the J Brief Reference: http://www.jsoftware.com/books/pdf/brief.pdf "Noun arguments to adverbs and conjunctions may be specified by m on the left and n on the right. Verb arguments are u and v and the derived functions use x and y to denote their arguments." x,y = arguments u,v = verbs m,n = nouns Reading the bond dictionary page again, we see the dyadic definition is: x m&v y ↔ m&v^:x y x u&n y ↔ u&n^:x y Looking at the sin definition: sin=: 1&o. m is 1 v is o. That would fall under the first case, x m&v y ↔ m&v^:x y Substituting in, we see that: (4 sin 1) -: ((1&o.^:4) 1) 1 Here's another way to spot the difference: Let's start by looking a the difference between m&v and u&n NB. m v y <-> (3&^) 2 NB. 3^2, m&v, square 3 9 ] m v y [ (m =. 3) [ (v=. ^) [ (y =. 2) 9 NB. y u n (^&3) 2 NB. 2^3, u&n, cube 2 8 ] y u n [ (y =. 2) [ (u=. ^) [ (n =. 3) 8 Now applying it dyadically: 2 (3&^) 1 NB. m&v 1 27 ((3&^)^:2) 1 27 3^3^1 27 NB. execute m v twice ] (m v (m v y)) [ (m =. 3) [ (v=. ^) [ (y =. 1) 27 2 (^&3) 1 NB. u&n, cube 1 ((^&3)^:2) 1 1 NB. execute y u twice ] (y u (y u n)) [ (y =. 1) [ (u=. ^) [ (n =. 3) 1 I find the letters m,n,u,v,y,x confusing. My best mnemonic is: I can remember n = noun. The letter before it (m) is also a noun I can remember v = verb. The letter before if (v) is also a verb I can remember y = is the last argument. The letter before it is x (left side) Hope this helps ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
