5 POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/exp2.html}
9 Portability problems fixed by Gnulib:
13 Portability problems not fixed by Gnulib:
16 This function is missing on some platforms:
17 MacOS X 10.5, FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, IRIX 6.5, OSF/1 4.0, Solaris 9, Interix 3.5.