Hello Raul, thanks for your reply. Now it makes sense, perfectly!
regards, Fausto 2015-02-19 16:01 GMT+01:00 Raul Miller <[email protected]>: > I think what you are looking for is the definition of the & > conjunction. You need to understand what it means to be a verb defined > that way. > > And, for this, you need to read the reference documentation: > > http://www.jsoftware.com/help/dictionary/d630n.htm states: > > x m&v y <---> m&v^:x y > > Here, x, m and y are nouns and v is the base verb. Let's call this "Rule A" > > It also states: > > x u&n y <---> u&n^:x y > > Here, x, n and y are nouns and u is the base verb. Let's call this "Rule B" > > (I say "base" verb, because u&n is a composite verb, derived from the > dyadic definition of u with n as its right argument.) > > ------------------- > > But it also states: > > m&v y is defined as m v y > > and > > u&n y is defined as y u n > > Let's call these "Rule C" and "Rule D". > > ------------------- > > In other words, > > ((2x&*) &1) 3 > > Rule D works with u: (2x&*), n: 1, y: 3, and gives us > > 3 (2x&*) 1 > > Rule B works with x: 3, u: (2x&*), y: 1 > > ((2x&*)^:3) 1 > > By the way, I should probably note that we need the outer parenthesis > there to prevent the 3 and 1 from being interpreted as a single token. > But there are a couple other ways we could have done that: > > (2x&*)^:(3) 1 > > or > > (2x&*)^:3 (1) > > We could also have used an expression to generate the value 1. For example: > > (2x&*)^:3 ]1 > > or > > (2x&*)^:3 >:0 > > ------------------- > > Does that make sense? > > Thanks, > > -- > Raul > > On Thu, Feb 19, 2015 at 9:08 AM, Fausto Saporito > <[email protected]> wrote: >> Hello Raul, >> >> thanks for the explanation. I'm still trying to understand it, but I >> thini I got it. >> >> Sorry my mistake about missing parenthesis. >> >> So, I'm missing the rule to understand this passage: >> >> ((2x&*) &1) 3 <---> ((2x&*)^:3) 1 >> >> But maybe this subject is too much advance for my J actual knowledge. >> >> thanks, >> Fausto >> >> >> 2015-02-19 14:48 GMT+01:00 Raul Miller <[email protected]>: >>> Please be careful here: >>> >>> 3 ((2x&*) &1) 3 >>> >>> is equivalent to each of these: >>> ((2x&*) &1) ((2x&*) &1) ((2x&*) &1) 3 >>> (((3(2x&*)1) (2x&*)1) (2x&*)1) >>> ((((2x&*)(2x&*)(2x&*)1) (2x&*)1) (2x&*)1) >>> ((8 (2x&*)1) (2x&*)1) >>> (((2x&*)(2x&*)(2x&*)(2x&*)(2x&*)(2x&*)(2x&*)(2x&*)1) (2x&*)1) >>> (256 (2x&*)1) >>> >>> and I'm not going to carry out the final step, which involves 256 >>> copies of the verb 2x&* >>> >>> Hopefully you can see why each of these expressions is equivalent. But >>> if something doesn't make sense, it's probably worth talking through >>> the issue (or at least showing a more gradual sequence of equivalences >>> for that step). >>> >>> On the other hand, >>> ((2x&*) &1^:3 3 >>> >>> is not a valid expression because of the unbalanced parenthesis. >>> >>> If you got rid of one of those left parenthesis, you'd get >>> (2x&*) &1^:3 3 >>> which is equivalent to >>> (2x&*) &1^:(3 3) >>> but that is a verb which you probably did not intend. >>> >>> If you instead insert a right parenthesis between the pair of threes, >>> you would get >>> ((2x&*) &1^:3) 3 >>> >>> which indeed is equivalent to your first expression. >>> >>> But note that you are not repeating three times 2x&* but instead are >>> repeating three times ((2x&*)1) in much the same manner as the >>> original expression. >>> >>> Thanks, >>> >>> -- >>> Raul >>> >>> >>> On Thu, Feb 19, 2015 at 8:11 AM, Fausto Saporito >>> <[email protected]> wrote: >>>> Hello Jose, >>>> >>>> I understand you are applying this identity : x u&n y <--> u&n^:x y >>>> >>>> But I cannot see the correct mapping in your expressions. >>>> I suppose this is an hook, so >>>> >>>> (u v) y --> y u v y >>>> >>>> 3 ((2x&*) &1) 3 >>>> >>>> ((2x&*) &1^:3 3 >>>> >>>> means repeat three times 2*1, i.e. 2*1*2*1*2*1 = 8 >>>> >>>> correct ? >>>> >>>> thanks, >>>> Fausto >>>> >>>> >>>> 2015-02-19 1:19 GMT+01:00 Henry Rich <[email protected]>: >>>>> If you're going to use dissect, get 3.6.42 (released today). Previous >>>>> versions had a confusing title for the verbs. >>>>> >>>>> Even with the picture it's amazing what this little phrase does. Two >>>>> nested >>>>> powers, with the result of one power feeding back into the exponent of the >>>>> next iteration of the same verb. >>>>> >>>>> Henry Rich >>>>> >>>>> >>>>> On 2/18/2015 7:12 PM, Jose Mario Quintana wrote: >>>>>> >>>>>> ((2x&*) &1) 3 >>>>>> 8 >>>>>> ((2x&*)^:3) 1 >>>>>> 8 >>>>>> ((3x&*) &1) 2 >>>>>> 9 >>>>>> ((3x&*)^:2) 1 >>>>>> 9 >>>>>> >>>>>> >>>>>> Does dissect >>>>>> >>>>>> >>>>>> http://www.jsoftware.com/jwiki/action/show/Vocabulary/Dissect?action=show&redirect=Addons%2Fdebug%2Fdissect >>>>>> >>>>>> help to follow the execution of the sentences? >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
