"CarbonLib" implies Mac OS 9 (or 8) — it's the classic Mac OS implementation of the Carbon API. The OS X implementation is Carbon.framework (or more precisely, various frameworks under its umbrella).
RegisterEventHotKey() is available "in CarbonLib 1.3 and later" according to Universal Interfaces.
"CarbonLib" implies Mac OS 9 (or 8) — it's the classic Mac OS implementation of the Carbon API. The OS X implementation is Carbon.framework (or more precisely, various frameworks under its umbrella).
RegisterEventHotKey() is available "in CarbonLib 1.3 and later" according to Universal Interfaces.