Hello!

I have discovered a little bug in GAP 3.4PL0:

gap> q := Indeterminate(Integers);
X(Integers)
gap> IsUnit(q^0);
false

The problem turns out to be that PolynomialRing(Integers).units gets
assigned the integers 1 and -1, not the polynomials 1*q^0, (-1)*q^0.

I therefore propose the following fix:

*** ring.g      1994/08/21 16:29:53     1.1
--- ring.g      1994/08/21 16:31:08
***************
*** 297,303 ****

      # add known units
      if IsBound(R.units)  then
!       P.units := Copy(R.units);
      fi;

      # set one and zero
--- 297,303 ----

      # add known units
      if IsBound(R.units)  then
!       P.units := List(R.units, u -> Polynomial( R, [u] ));
      fi;

# set one and zero

Harald

--
Harald Boegeholz |   hwb@mathematik.uni-stuttgart.de
                 |   os2a@ftp.uni-stuttgart.de