def obfn_g(self, Y):
        r"""Compute :math:`g(\mathbf{y}) = g_0(\mathbf{y}_0) +
        g_1(\mathbf{y}_1)` component of ADMM objective function.
        """

        return self.obfn_g0(self.obfn_g0var()) + \
            self.obfn_g1(self.obfn_g1var())