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
