Re: Some questions: built-in operators and exponent markers

To redefine the built-in operator "!", try this in your Maxima session:

:lisp (remprop '$! 'mheader)
:lisp (remprop '$! 'led)

and then

postfix ("!");
x ! := x * %i;

Then I get:

x!;
 => %i*x

100!;
 => 100*%i

etc.

You might consider using an otherwise-undefined operator, such as "i".

postfix ("i");
x i := x * %i;

x i;
 => x*%i

100;
 => 100*%i

I don't think it's possible to change the exponent marker for
bigfloats from b to p except for searching the source code (probably
src/nparse.lisp but possibly elsewhere) for the place where bigfloats
are parsed, and look for an instance of the characters #\B and #\b,
and replace them with #\P and #\p. I haven't tried it.

Hope this helps,

Robert