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

POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/acos.html}

Gnulib module: acos

Portability problems fixed by Gnulib:
@itemize
@end itemize

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