module Functions
      public :: fun
      contains
         function fun(t) result (r)
            real, intent(in) :: t
            real  :: r
            r = sqrt(abs(t)) + 5.0*t**3
         end function fun
      end module Functions

      program TPK
!     The TPK Algorithm
!     F style
      use Functions
      integer		    :: i
      real                  :: y
      real, dimension(0:10) :: a
      read *, a
      do i = 10, 0, -1      ! Backwards
         y = fun(a(i))
         if ( y < 400.0 ) then
            print *, i, y
         else
            print *, i, " Too large"
         end if
      end do
      end program TPK