[Maxima-discuss] ((MPLUS SIMP FACTORED) 2 3) -> 3 + 2

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

Hi list,

I know that this is not supposed to work, but I think that the
question is interesting anyway...

In this thread from mid-august -

  https://sourceforge.net/p/maxima/mailman/message/58807287/

...I learned that the result of factor(12345678) is not simplified
because is starts with (MTIMES SIMP FACTORED). A few hours ago I
decided to test if I could use that same trick with other arithmetic
expressions, and it ALMOST worked. These three expressions

  factor(12345678);
  lambda([], 2 * 3^2 * 47 * 14593);
  lambda([], 2+3);

are, respectively:

        ((MTIMES SIMP FACTORED) 2 ((MEXPT SIMP) 3 2) 47 14593)
  ((LAMBDA SIMP) ((MLIST)) ((MTIMES) 2 ((MEXPT) 3 2) 47 14593))
  ((LAMBDA SIMP) ((MLIST)) ((MPLUS) 2 3))

I tried to run this in a REPL,

  format0(o) := format("~s",o);

  o  : factor(12345678);
  o2 : lambda([], 2 * 3^2 * 47 * 14593);
  o3 : lambda([], 2+3);

  format0(o);
  format0(o2);
  format0(o3);

  to_lisp();
      (defun $unlambda (olambda)
        (let* ((obody (cddr olambda))
               (oop   (caaar obody))
               (oargs (cdar obody)))
          `((,oop simp factored) ,@oargs)
          ))
      #$o$
      #$o2$
      #$o3$
      ($unlambda #$o2$)
      ($unlambda #$o3$)
    (to-maxima)

  unlambda(o2);
  unlambda(o3);
  format0(unlambda(o3));

And ta-da: the result of

  format0(unlambda(lambda([], 2+3)));

is this,

  ((MPLUS SIMP FACTORED) 2 3)

that looks promising... but Maxima prints the result of

  unlambda(lambda([], 2+3));

as

  3 + 2

instead of the "2 + 3" that I was hoping for.

Any comments?
  Cheers =) =) =),
    Eduardo Ochs