Section 11,3: ACOSD

 ACOSD (real-number)

 A function that returns the arc cosine of the argument in degrees.
 The value of the argument must be between 0 (exclusive) and 1
 (inclusive).

 +------+---------+----------+------------+-------------+        
 | Args | Generic | Specific |  Argument  | Result Type |
 +------+---------+----------+------------+-------------+
 |  1   |  ACOSD  |  ACOSD   | REAL*4     | REAL*4      |
 |      |         |  DACOSD  | REAL*8     | REAL*8      |
 |      |see note |  QACOSD  | REAL*16    | REAL*16     |
 +------+---------+----------+------------+-------------+

 NOTE: QACOSD is not available in DEC Fortran.