The library cases N201 - N213 provide a variety of linear equation solvers, ranging from Jacobi to Multigrid methods. I'm wondering if they are all available without additional purchase. I've tried those cases but I am not sure those solvers are actually working. I examined the 'GREX3.for' and I found there are no corresponding keywords for the solvers described in those library cases except Gauss-Seidel and conjugate gradient solvers. Could anyone tell me if they are actually built in PHOENICS? I am using PHOENICS 3.4. Thanks.