VMS Help FORTRAN, Intrinsic Procedures, DIM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  DIM (number, number)

  A function that returns the value of the first argument minus the
  minimum (MIN) of the two arguments.

  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |   2  |  DIM    | IIDIM    | INTEGER*2  | INTEGER*2   |
  |      |         | JIDIM    | INTEGER*4  | INTEGER*4   |
  |      |         | DIM      | REAL*4     | REAL*4      |
  |      |         | DDIM     | REAL*8     | REAL*8      |
  |      |         | QDIM     | REAL*16    | REAL*16     |
  +------+---------+----------+------------+-------------+
  See also the IDIM intrinsic function.