  [0.00]{}  ![\[fig:MPFAbfs\] Basis function for the internal block of a regular 0$\times$0 partition: (a) primal grid and coarse nodes ((0,0) circle (.0ex);); (b) support boundary ((0,0) rectangle (0ex, 0ex);), edge ((0,0) rectangle (0ex, 0ex);) and internal cells ((0,0) rectangle (0ex, 0ex);); (c) MsRSB basis function using the original fine-scale system; and (d) MsRSB basis function using the filtered fine-scale system. The convergence criteria is $||e_{it}||_{\infty} < 00^{-00}$, where $e_{it}$ is the smoother update on the internal cells (see algorithm \[alg:EnhancedMsRSB\]). However as the case with the original linear system diverges, the basis function obtained after 00 iterations is plotted in (c).](./MPFA_0x0_