SCM_SYS_FDSET_P  2740 src/gauche.h   #define SCM_SYS_FDSET_P(obj)    (SCM_XTYPEP(obj, SCM_CLASS_SYS_FDSET))
SCM_SYS_FDSET_P  2750 src/gauche.h   #define SCM_SYS_FDSET_P(obj)    (FALSE)