5 POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/floor.html}
7 Gnulib module: floor or floor-ieee
9 Portability problems fixed by either Gnulib module @code{floor} or @code{floor-ieee}:
13 Portability problems fixed by Gnulib module @code{floor-ieee}:
17 Portability problems not fixed by Gnulib: