ACOS

 ACOS (real-number)

 Class:  Elemental function - Generic

 Returns the arc cosine of the argument in radians.  The absolute
 value of the argument must be less than or equal to 1.

 +------+---------+----------+------------+-------------+        
 | Args | Generic | Specific |  Argument  | Result Type |
 +------+---------+----------+------------+-------------+
 |  1   | ACOS    | ACOS     | REAL*4     | REAL*4      |
 |      |         | DACOS    | REAL*8     | REAL*8      |
 |      |         | QACOS    | REAL*16    | REAL*16     |
 +------+---------+----------+------------+-------------+