Language Environment provides a set of math routines, including routines for exponentiation. For most commonly used routines, Language Environment produces more accurate results than OS PL/I. Some of the Language Environment routines also have better performance than OS PL/I. You should use the Language Environment-provided math routines.
Language Environment also provides the OS PL/I math routines to help you to migrate to Language Environment; however, the OS PL/I math routines are provided for compatibility only and will be withdrawn in the future.
If your application must use the OS PL/I math routines under Language Environment, place SIBMMATH in front of SCEELKED when you link-edit your object module.