             //dg::blas2::gemv( LaplacianM_perp, temp, y[i]);
             //dg::blas1::axpby( -nu_, y[i], 0., y[i]);
             dg::blas2::gemv( LaplacianM_perp, x[i], y[i]);
-            dg::blas1::scal( y[i], nu_);
+            dg::blas1::scal( y[i], -nu_);
         }
     }
     dg::Elliptic<Geometry, Matrix, container>& laplacianM() {return LaplacianM_perp;}

        double Gphi = -blas2::dot( phi[0], w2d, lapy[0]);
        double Gpsi = -blas2::dot( phi[1], w2d, lapy[1]);
        //std::cout << "ge "<<Ge<<" gi "<<Gi<<" gphi "<<Gphi<<" gpsi "<<Gpsi<<"\n";
        ediff_ = -nu*( Ge + Gi - Gphi + Gpsi);
    }

    for( unsigned i=0; i<y.size(); i++)

    void operator()( std::vector<container>& x, std::vector<container>& y)
    {
        /* x[0] := N_e - 1
         * x[2] := N_i - 1 
         */
        for( unsigned i=0; i<x.size(); i++)
        {
