'Return the quotient homomorphism to self.
That is, return the natural map from ``self.base`` to ``self``.
>>> from sympy.abc import x
>>> from sympy import QQ
>>> M = (QQ.old_poly_ring(x).free_module(2) / [(1, x)]).submodule([1, 0])
>>> M.quotient_hom()
Matrix([
[1, 0], : <[1, 0], [1, x]> -> <[1, 0] + <[1, x]>, [1, x] + <[1, x]>>
[0, 1]])'

def quotient_hom(self):

    return self.base.identity_hom().quotient_codomain(self.killed_module)
