program main
  implicit none
  call dispatch(p1, 111)
contains
  subroutine dispatch(p, n) ! 再帰的な手続きに RECURSIVE が付いていない。
    interface
      subroutine p
      end subroutine
    end interface
    integer, intent(in) :: n
    integer x(1000, 1000)
    x = n
    print *, 'Hello', x(1, 1)
    call p
    print *, 'Goodbye', x(1, 1)
  end subroutine
  subroutine p1
    call dispatch(p2, 999)
  end subroutine
  subroutine p2
    print *, 'Hello World'
  end subroutine
end program