interface
    subroutine PetscFVSetComponentName(fvm, comp, name, ierr)
        use petscdmdef
        PetscFV :: fvm
        PetscInt, intent(in) :: comp
        character(len=*) :: name
        PetscErrorCode, intent(out) :: ierr
    end subroutine PetscFVSetComponentName

    subroutine PetscFVView(fvm, vin, ierr)
        use petscdmdef
        PetscFV :: fvm
        PetscViewer :: vin
        PetscErrorCode, intent(out) :: ierr
    end subroutine PetscFVView

    subroutine PetscFVSetType(fvm, typename, ierr)
        use petscdmdef
        PetscFV :: fvm
        character(len=*) :: typename
        PetscErrorCode, intent(out) :: ierr
    end subroutine PetscFVSetType

    subroutine PetscDSView(prob, vin, ierr)
        use petscdmdef
        PetscDS :: prob
        PetscViewer :: vin
        PetscErrorCode, intent(out) :: ierr
    end subroutine PetscDSView
end interface