def __init__(self,ring,ringstr="",list=None):
'''Constructor for an ideal in a solvable polynomial ring.
'''
self.ring = ring;
if list == None:
sr = StringReader( ringstr );
tok = GenPolynomialTokenizer(ring.ring,sr);
self.list = tok.nextSolvablePolynomialList();
else:
self.list = pylist2arraylist(list);
self.pset = OrderedPolynomialList(ring.ring,self.list);
