d doesn’t appear in the result of 13 : because d is defined locally in a. In my previous experience of 13 :, it does its best to “factor” intermediate values like d with trains, but here it seems to have slipped up and treated a as dyadic. 13 : should have returned
] (([: a [: a ]) + [: a [ - a) <: instead of ] (([: a a ) + [: a [ - a) <: Louis > On 28 Dec 2016, at 01:05, 'Pascal Jasmin' via Programming > <[email protected]> wrote: > > d is a noun in 3 : > it does not appear in result of 13 > > 13 : is buggy. The tacit version you want is > > a =: (a@:a@:<: + ] a@:([ - a@]) <:)`1:@.(<:&2) > > > > ----- Original Message ----- > From: Louis de Forcrand <[email protected]> > To: [email protected] > Sent: Tuesday, December 27, 2016 6:07 PM > Subject: [Jprogramming] Strange 13 : '...' behavior > > From: http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence > <http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence> > > JVERSION > Engine: j805/j64/darwin > Beta-12: commercial/2016-09-30T16:11:35 > Library: 8.05.07 > Platform: Darwin 64 > Installer: J805 install > InstallPath: /users/louisdeforcrand/applications/j64-805 > Contact: www.jsoftware.com > a=: 3 : '(a a d)+a y-a d=.<:y'`1:@.(<:&2) > a"0>:i.10 NB. correct behavior > 1 1 2 2 3 4 4 4 5 6 > a=: 13 : '(a a d)+a y-a d=.<:y'`1:@.(<:&2) > a"0>:i.10 NB. incorrect behavior > 1 1 2 3 4 5 6 7 8 9 > a > (] (([: a a) + [: a [ - a) <:)`1:@.(<:&2) > > Anybody know what’s going on? > > Louis > > ---------------------------------------------------------------------- > 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
