NAME
    cgIsAnnotation - determine if a CGannotation references a valid Cg
    annotation

SYNOPSIS
      #include <Cg/cg.h>

      CGbool cgIsAnnotation(CGannotation ann);

PARAMETERS
    ann     Specifies the annotation handle to check.

DESCRIPTION
    cgIsAnnotation returns CG_TRUE if ann references a valid annotation,
    CG_FALSE otherwise.

ERRORS
    This function generates no errors.

