Guardian Native C Library Calls Reference Manual (G06.28+, H06.05+)

Guardian Native C Library Calls (a - e) acos(3)
STANDARDS CONFORMANCE
This function conforms to the XPG4 Version 2 specication with extensions when used for IEEE
oating-point format data. This function conforms to the XPG4 Version 2 specication without
extensions when used for Tandem oating-point data.
The XPG4 Version 2 specication leaves some features to the implementing vendor to dene.
The following feature is affected in the HP implementation:
For IEEE oating-point values, errno is not set to [EDOM] when the
value of x is NaN.
527192-007 Hewlett-Packard Company 19