@node acos
@section @code{acos}
@findex acos

POSIX specification: @url{http://www.opengroup.org/susv3xsh/acos.html}

Gnulib module: ---

Portability problems fixed by Gnulib:
@itemize
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@end itemize