Portability problems fixed by Gnulib module @code{ceilf-ieee}:
@itemize
@item
-This function returns a positive zero for an argument between -1 and 0
+This function returns a positive zero for an argument between @minus{}1 and 0
on some platforms:
-MacOS X 10.5, AIX 7.1, OSF/1 5.1.
+Mac OS X 10.5, AIX 7.1, OSF/1 5.1.
@item
This function returns a positive zero for a minus zero argument
on some platforms: