int applyToSet (set * list, int (*somefunc) (void *, va_list),...);
int applyToSetFTrue (set * list, int (*somefunc) (void *, va_list),...);
set *unionSets (set *, set *, int);
int applyToSet (set * list, int (*somefunc) (void *, va_list),...);
int applyToSetFTrue (set * list, int (*somefunc) (void *, va_list),...);
set *unionSets (set *, set *, int);