Section 11,40: IDIM

 IDIM (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   |  IDIM   |   --     | INTEGER*1  | INTEGER*1   |
 |      |         | IIDIM    | INTEGER*2  | INTEGER*2   |
 |      |         | JIDIM    | INTEGER*4  | INTEGER*4   |
 |      |see note | KIDIM    | INTEGER*8  | INTEGER*8   |
 +------+---------+----------+------------+-------------+

 NOTE: KIDIM is only available on AXP systems.
 See also the DIM intrinsic function.