def __init__(self,module,modstr="",list=None):
'''Constructor for sub-module over a solvable polynomial ring.
'''
self.module = module;
if list == None:
sr = StringReader( modstr );
tok = GenPolynomialTokenizer(module.ring,sr);
self.list = tok.nextSolvableSubModuleList();
else:
self.list = pylist2arraylist(list);
self.mset = OrderedModuleList(module.ring,self.list);
self.cols = self.mset.cols;
self.rows = self.mset.rows;
