module modTsTest
 implicit none
 contains
 subroutine PostTimeStep(ts,ierr)
#include "finclude/petsc.h"
#include "finclude/petscts.h"
 TS :: ts
 PetscErrorCode :: ierr
 end subroutine PostTimeStep

end module modTsTest
 program TsTest
 use modTSTest
  implicit none
#include "finclude/petsc.h"
#include "finclude/petscts.h"
  MPI_Comm :: comm
  TS :: ts
  Mat :: A
  Vec :: solx
  PetscErrorCode :: ierr

  call PetscInitialize(PETSC_NULL_CHARACTER, ierr)
   comm = PETSC_COMM_SELF
   call TSCreate(comm,ts,ierr)
   call TSSetProblemType(ts, TS_LINEAR,ierr)
   call TSSetMatrices(ts,A,PETSC_NULL_FUNCTION,PETSC_NULL_INTEGER,PETSC_NULL_FUNCTION,DIFFERENT_NONZERO_PATTERN,PETSC_NULL_INTEGER,ierr)
   call TSSetSolution(ts,solx,ierr)
   call TSSetType(ts,TSCRANK_NICHOLSON,ierr)
   call TSSetPostStep(ts,PostTimeStep,ierr)
   call TSSetFromOptions(ts,ierr)
  call PetscFinalize(ierr)

 end program TsTest