If you type in :
(%i5) kill(all);
(%o0) done
(%i1) 3/4;
(%o1) 3/4
(%i2) 3/2;
(%o2) 3/2
(%i3) 3/1;
(%o3) 3
(%i4) 3/0;
expt: undefined: 0 to a negative exponent.
-- an error. To debug this try: debugmode(true);
Since Maxima is not trying to compute the answer, it just simplifies the
input in these cases, why the error? Would it be better if you could get
the unsimplified form back?
(%i5) 3/0;
(%o5) 3/0
Rich