anchor.diff:    logical :: status
     integer, intent(IN) :: kind
     status = .false.
  -  if(kind < 31 .or. kind < 0) status = islevel(kind)==1
  +  if(kind <= Max_Kind .and. kind >= 0) status = islevel(kind)==1
   end function is_level
   !===============================================================================================
   function ascending(kind) result(status) ! is this kind "ascending" (larger value higher in atmosphere) ?
  
positive.code:   logical :: status
    integer, intent(IN) :: kind
    status = .false.
    if(kind < 31 .or. kind < 0) status = order(kind)==-1
  end function descending
  !===============================================================================================
  function is_invalid_kind(kind) result(status) ! is this kind invalid ?
  
negative.code:   logical :: status
    integer, intent(IN) :: kind
    status = .false.
    if(kind <= Max_Kind .and. kind >= 0) status = order(kind)==1
  end function ascending
  !===============================================================================================
  function descending(kind) result(status) ! is this kind "descending" (larger value lower in atmosphere) ?
  