@node acos
@subsection @code{acos}
@findex acos

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/functions/acos.html}

Gnulib module: acos
@mindex acos

Portability problems fixed by Gnulib:
@itemize
@end itemize

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