Re: [Maxima-discuss] What is the variable `result' in functions like `dim-%at'?

[Eduardo O. <edu...@gm...>]

I understood some parts - but at least I have better questions now.
If I run this simpler example,

  trace(?dim\-%at);
  o : 'at(f(x), x=a);

I get:

  (%i1) trace(?dim\-%at);
  (%o1)                              [dim-%at]
  (%i2) o : 'at(f(x), x=a);
                         │
  1 Call   dim\-%at [f(x)│     , 0( , ), 2, o, %, ()]
                         │x = a
  1 Return dim\-%at 0((d-vbar, 2, 1, │), ), x, (, f, (0, 0),  , ), 2, o, %,
()
                                        │
  (%o2)                             f(x)│
                                        │x = a
  (%i3)

My first impression is that dim-%at was called with two arguments -
my `o' and this "call to 0",

  apply(\0, reverse(charlist("(%o2) ")));

and it returned this other "call to 0", in which some arguments looks
like tuples. I don't know how to synthesize them from Maxima yet, so
in the code below I replaced them with strings just to get something
that looks like the thing after the "Return dim\-%at" above...

  o2    : reverse(charlist("(%o2) "));
  ofx   : reverse(charlist("f(x)"));
  ovbar : ["(d-vbar, 2, 1, │)"];
  o00   : ["(0, 0)"];
            append(ovbar, ofx, o00, o2);
  apply(\0, append(ovbar, ofx, o00, o2));

What are the "calls to 0" and the "tuples" in the output of trace
above?

  Thanks in advance, more later, etc...
    Eduardo



On Sat, 26 Apr 2025 at 05:19, Michel Talon <ta...@lp...> wrote:

> First try thefollowing commands:
>
> trace(?dim\-%at);
>
> atvalue ('diff (f(x,y), x), x = 0, 1 + y);
>
> printprops (all, atvalue);
>
> I think what appears can be understood readily.
>