'Generate a submodule.
>>> from sympy.abc import x, y
>>> from sympy import QQ
>>> M = QQ.old_poly_ring(x, y).free_module(2).submodule([x, x + y])
>>> M
<[x, x + y]>
>>> M.contains([2*x, 2*x + 2*y])
True
>>> M.contains([x, y])
False'

def submodule(self, *gens, **opts):

    return SubModulePolyRing(gens, self, **opts)
