(self)
return self._img
r"""
        Compute the image of ``self``.

        That is, if ``self`` is the homomorphism `\phi: M \to N`, then compute
        `im(\phi) = \{\phi(x) | x \in M \}`.  This is a submodule of `N`.

        >>> from sympy import QQ
        >>> from sympy.abc import x
        >>> from sympy.polys.agca import homomorphism

        >>> F = QQ.old_poly_ring(x).free_module(2)
        >>> homomorphism(F, F, [[1, 0], [x, 0]]).image() == F.submodule([1, 0])
        True
r"""
        Compute the image of ``self``.
r Compute the image of self .
def image(self):
        r"""
        Compute the image of ``self``.

        That is, if ``self`` is the homomorphism `\phi: M \to N`, then compute
        `im(\phi) = \{\phi(x) | x \in M \}`.  This is a submodule of `N`.

        >>> from sympy import QQ
        >>> from sympy.abc import x
        >>> from sympy.polys.agca import homomorphism

        >>> F = QQ.old_poly_ring(x).free_module(2)
        >>> homomorphism(F, F, [[1, 0], [x, 0]]).image() == F.submodule([1, 0])
        True
        """
        if self._img is None:
            self._img = self._image()
        return self._img
def image ( self ) : if self . _img is None : self . _img = self . _image ( ) return self . _img