sage: K.<a,b> = NumberField([x^2 + 1, x^2 + 2])
sage: A = K.absolute_field('z')
sage: I = A.factor_integer(3)[0][0]
sage: from_A, to_A = A.structure()
sage: G = [from_A(z) for z in I.gens()]; G
[3, (-2*b - 1)*a + b - 1]
sage: K.fractional_ideal(G)
---------------------------------------------------------------------------
<type 'exceptions.TypeError'>             Traceback (most recent call last)

/Users/was/s/devel/sage-main/sage/rings/number_field/<ipython console> in <module>()

/Users/was/s/local/lib/python2.5/site-packages/IPython/Prompts.py in __call__(self, arg)
    521 
    522             # and now call a possibly user-defined print mechanism
--> 523             manipulated_val = self.display(arg)
    524             
    525             # user display hooks can change the variable to be stored in

/Users/was/s/local/lib/python2.5/site-packages/IPython/Prompts.py in _display(self, arg)
    545         """
    546 
--> 547         return self.shell.hooks.result_display(arg)
    548 
    549     # Assign the default display method:

/Users/was/s/local/lib/python2.5/site-packages/IPython/hooks.py in __call__(self, *args, **kw)
    132             #print "prio",prio,"cmd",cmd #dbg
    133             try:
--> 134                 ret = cmd(*args, **kw)
    135                 return ret
    136             except ipapi.TryNext, exc:

/Users/was/s/local/lib/python2.5/site-packages/IPython/hooks.py in result_display(self, arg)
    160     
    161     if self.rc.pprint:
--> 162         out = pformat(arg)
    163         if '\n' in out:
    164             # So that multi-line strings line up with the left column of

/Users/was/s/local/lib/python2.5/pprint.py in pformat(self, object)
    109     def pformat(self, object):
    110         sio = _StringIO()
--> 111         self._format(object, sio, 0, 0, {}, 0)
    112         return sio.getvalue()
    113 

/Users/was/s/local/lib/python2.5/pprint.py in _format(self, object, stream, indent, allowance, context, level)
    127             self._readable = False
    128             return
--> 129         rep = self._repr(object, context, level - 1)
    130         typ = _type(object)
    131         sepLines = _len(rep) > (self._width - 1 - indent - allowance)

/Users/was/s/local/lib/python2.5/pprint.py in _repr(self, object, context, level)
    193     def _repr(self, object, context, level):
    194         repr, readable, recursive = self.format(object, context.copy(),
--> 195                                                 self._depth, level)
    196         if not readable:
    197             self._readable = False

/Users/was/s/local/lib/python2.5/pprint.py in format(self, object, context, maxlevels, level)
    205         and whether the object represents a recursive construct.
    206         """
--> 207         return _safe_repr(object, context, maxlevels, level)
    208 
    209 

/Users/was/s/local/lib/python2.5/pprint.py in _safe_repr(object, context, maxlevels, level)
    290         return format % _commajoin(components), readable, recursive
    291 
--> 292     rep = repr(object)
    293     return rep, (rep and not rep.startswith('<')), False
    294 

/Users/was/s/local/lib/python2.5/site-packages/sage/rings/number_field/number_field_ideal.py in __repr__(self)
    215 
    216     def __repr__(self):
--> 217         return "Fractional ideal %s"%self._repr_short()
    218 
    219     def _repr_short(self):

/Users/was/s/local/lib/python2.5/site-packages/sage/rings/number_field/number_field_ideal.py in _repr_short(self)
    232         # makes things insanely slow in general.
    233         # When I fix this, I *have* to also change the _latex_ method.
--> 234         return '(%s)'%(', '.join([str(x) for x in self.gens_reduced()]))
    235 
    236     def __div__(self, other):









/Users/was/s/local/lib/python2.5/site-packages/sage/rings/number_field/number_field_ideal_rel.py in gens_reduced(self)
     84             S = L['x']
     85             gens = L.pari_rnf().rnfidealtwoelt(self.pari_rhnf())
---> 86             gens = [ L(R(x.lift().lift())) for x in gens ]
     87             ## Make sure that gens[1] is in L, not K
     88             Lcoeff = [ L(x) for x in list(gens[1].polynomial()) ]

/Users/was/s/local/lib/python2.5/site-packages/sage/rings/number_field/number_field.py in __call__(self, x)
   3321             return self.base_field()(x)
   3322         
-> 3323         return self._element_class(self, x)
   3324 
   3325     def _coerce_impl(self, x):

/Users/was/s/devel/sage-main/sage/rings/number_field/number_field_element.pyx in sage.rings.number_field.number_field_element.NumberFieldElement.__init__()
    231         num = f * den
    232         for i from 0 <= i <= num.degree():
--> 233             (<Integer>ZZ(num[i]))._to_ZZ(&coeff)
    234             ZZX_SetCoeff( self.__numerator, i, coeff )
    235 

/Users/was/s/devel/sage-main/sage/rings/number_field/integer_ring.pyx in sage.rings.integer_ring.IntegerRing_class.__call__()

<type 'exceptions.TypeError'>: Unable to coerce -b - 2 to an integer