Thanks again, Joe. No I wasn't missing the picture in the box. Have pored over it many times. I just hadn't seen how the OP's initial formulation of a MONADIC verb as a hook was being tranformed to the dyadic formula. Once I realised that the *application* of the hook yielded something dyadic. (x was now the initial y, and y was gx) then all was clear.
Just FYI. I thought you might like the insight into the workings of the mind of a noob, since you went to all that trouble to help... On 3 May 2014 18:27, Alex Giannakopoulos <[email protected]> wrote: > Yup, got it now. > ((m&v)(n&u))y > => > y (m&v)((n&u)y) NB. Definition of hook > > Since x (m&v) y <=> m&v ^: x y > y (m&v) ((n&u) y) <=> (m&v) ^: y ((n&u) y) > > (The confusing bit was that the y in the initial formulation was the x in > the dictionary formula, and the y was the whole of ((n&u) y)) > > Thanks all > > > > > On 3 May 2014 18:13, Alex Giannakopoulos <[email protected]> wrote: > >> @Joe: Thanks, I use the same notation for m,n,u,v,x and y (I'd have >> thought it was obvious. So many other things seem to be around here...) >> BTW, you are right it is confusing. >> >> >> @R.E.Boss: thanks for the link, and even repeating it. I assure you I >> have read that page many times before. >> I must apologize that my level of intelligence does not immediately >> recognize that what is is listed there completely resolves the OP's >> question. You'll just have to accept that some dim people like to use J >> too :) >> >> As I cannot immediately see how the info there will reduce the OP's >> (m&v n&u) y >> to >> (m&v) ^:y (n&u y) >> >> I will read Joe's post again more attentively, he seems to be steering me >> the way I want to go. >> Please don't bother explaining it any more, I think there is enough info >> for a determined soul, plus I enjoy the challenge. I hope the OP found >> this as useful and informative as I did. >> >> >> >> On 3 May 2014 17:06, Joe Bogner <[email protected]> wrote: >> >>> > 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 >>> >> >> > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
