There was no warning that negative numbers were not allowed. Especially considering that the "equivalent" phrase accommodates a negative number.
+:^:_5 (1) 0.03125 _5(+:@[&0)1 |domain error | _5 (+:@[&0)1 http://www.jsoftware.com/help/dictionary/d630n.htm JVERSION Engine: j807/j64/darwin Beta-f: commercial/2018-06-28T12:14:57 Library: 8.07.16 Platform: Darwin 64 Installer: J807 install InstallPath: /users/brian/j64-807 Contact: www.jsoftware.com On Thu, Aug 9, 2018 at 6:03 AM, Martin Kreuzer <[email protected]> wrote: > ** Brian > > Took your hint and managed to put together a named verb which does work > even for lists > > p=. 13 : '1(+:@[&0)~y' > p i.5 > 1 2 4 8 16 > pt=. 1 (+:@[&0)~ ] > pt i.5 > 1 2 4 8 16 > > but for some reason not for negative arguments .. > > p -i.5 > |domain error: p > | p-i.5 > > -M > > > > -- (B=) ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
