# Re: [Jchat] How close is J to APL?

```I don't really want to debate whether 0-origin or 1-origin is better (you
can find a record of a previous discussion in Is Index Origin 0 a Hindrance?
<http://www.jsoftware.com/papers/indexorigin.htm>), but I do take issue
with your statement that mathematics has origin one.  Consider the
following power series, among many other such series.```
```
+/ (⍵*⍳n) ÷ !⍳n      ⍝ APL
+/ (x*i.n) % ! i.n   ⍝ J

One way to think about index origin, is to consider the question whether 1
is a prime. http://www.jsoftware.com/papers/APLDesignExercises1.htm#14

⎕io *delenda est*.

On Thu, May 17, 2018 at 12:48 PM, Don Guinn <dongu...@gmail.com> wrote:

> Perhaps the mistake was for APL to include an index origin of zero. FORTRAN
> has index origin one and so does mathematics. The idea of index origin zero
> came from computer programming as it allows the first element of an array
> to fall at the address. Software convenience. PLI was interesting in that
> it allowed the first element of an array to be DECLAREd as any number.
> Basic cheats. When DIMensioning an array as size N it creates N+1 elements
> with the first element index zero. But if one wants, there is an index N
> element also so one can start from one.
>
> On Thu, May 17, 2018 at 1:35 PM, John Baker <bakerj...@gmail.com> wrote:
>
> > As I recall Carthage was destroyed. Maybe the scourge of index origin 1
> > will follow.
> >
> > Cheers
> >
> > Sent from my iPhone
> >
> > > On May 17, 2018, at 1:23 PM, Roger Hui <rogerhui.can...@gmail.com>
> > wrote:
> > >
> > > If it used alpha and omega then it's not tacit.  Tacit means no
> explicit
> > > mention of the function arguments; the term "tacit" was invented in
> 1991
> > > http://www.jsoftware.com/papers/TacitDefn.htm .  Tacit definition was
> > first
> > > used APL\360, way back in 1966, as in +/ , but it was not recognized as
> > > tacit.  What made tacit fly were forks, first implemented in J in
> version
> > > 0.1.  In fact, tacit defn was implemented in J long before explicit
> defn.
> > >
> > >
> > >
> > >> On Thu, May 17, 2018 at 12:14 PM, Don Guinn <dongu...@gmail.com>
> wrote:
> > >>
> > >> Tacit came out first in APL. Used alpha and omega. First time I saw
> +/÷#
> > >> and thought "What is that??" (Sorry. Couldn't find rho.)
> > >>
> > >>> On Thu, May 17, 2018, 11:24 AM David Lambert <b49p23t...@gmail.com>
> > wrote:
> > >>>
> > >>> "APL and J are conceptually similar. That is, one knowing one
> language
> > >> can
> > >>> easily pick up the other. "
> > >>> Verbs and rank thinking are easily transferred.  Tacit programming
> was
> > >> new
> > >>> and difficult for me, having used APL, APL2, and a VAX-VMS APL from
> > DEC.
> > >>> .QQ is quote quad, .BX is box, etceteras.
> > >>> ------------------------------------------------------------
> ----------
> > >>> 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
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm```