If k = 1, we explicitly invert a 4 · 4 matrix to obtain the
solution. If k > 1, we solve Eq. (A.3) by performing a
J . K i m / C o m p u t . M e t h o d s A p p l . M e c h . E n g r g . 1 9 6 ( 2 0 0 7 ) 4 7 7 9 – 4 7 8 8 4787
FAS k -grid cycle using f? c m
k?1 ;? l
m? 1
2
k?1 g
as an initial approximation: