“…D P -' I 2 ] ) = --(6,DX"+ 6,DX"' ' I 2 ) + +dcn, ,11 ( D Z , DX ) + -(6tDC"-"2,6tDC"-'~2) +~6 s , m~,1 2 ( D Z , D C ) In addition, typical nonlinear relationships of the following form can be derived: STABILITY AND CONVERGENCE OF SOME FINlTE ELEMENT ALGORITHMS 9x7 + (1 + 5 ) ( [ D u n + ( Du" + D u n -) I ,DE", [dtDC"+112 + d,i7) …”