+SR_API int sr_rational_eq(const struct sr_rational *a, const struct sr_rational *b);
+SR_API int sr_rational_mult(struct sr_rational *res, const struct sr_rational *a,
+ const struct sr_rational *b);
+SR_API int sr_rational_div(struct sr_rational *res, const struct sr_rational *num,
+ const struct sr_rational *div);