5 POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/isinf.html}
9 Portability problems fixed by Gnulib:
12 This macro is missing on some platforms:
13 AIX 5.1, IRIX 6.5, Solaris 11.4.
16 Portability problems not fixed by Gnulib:
19 This macro returns an unspecified result when given noncanonical values
20 such as unnormalized numbers, pseudo-denormals, pseudo-NaNs,
21 pseudo-Infinities, and pseudo-zeroes.