MODULE testnan ;
FROM Builtins IMPORT isnan ;
FROM libc IMPORT printf, exit ;
VAR
x: REAL ;
BEGIN
x := 0.0 / 0.0 ;
IF isnan (x) = 1
THEN
printf ("success isnan working from module Builtins\n")
ELSE
printf ("failure isnan is not working from module Builtins\n") ;
exit (1)
END
END testnan.