After discovery of the implicit none (type, external) statement for disabling implicit procedures (thanks to Barry for the suggestion), I used that in my code to good effect.
However, it also showed that were some routines I call that did not have explicit Fortran interfaces, and maybe they exist but I just didn’t include the right modules. Here are the ones I’m missing: MatShellSetOperation PetscOptionGetString PetscViewerASCIIPrintF VecSetValue KSPMonitorSet Do the Fortran interfaces exist for these? If not can they be added? Thanks, Randy
