Infinitely Deep Graph Transformation Networks

$$ \min_{\Theta_v, \Theta_e, W_{ev}, W_{ve}, \Omega} \mathcal{L}_1(F', g_{\Theta_e}(H_v)) + \mathcal{L}_2(E', f_{\Theta_e}(H_e)) , \\ \text{subject to: } H_e = \phi(W_{ve} H_v B ) , \\ H_v = \phi( W_{ev} \phi( W_{ve} H_v B ) B^{\intercal} +b_{\Omega}(E_0, F_0)) ,\\ \lambda_{pf}(B B^{\intercal}) \lambda_{pf} ( W_{ev}^{|\cdot|} W_{ve}^{|\cdot|}) <1 . $$