+SCM_API void scm_floor_divide (SCM x, SCM y, SCM *q, SCM *r);
+SCM_API SCM scm_floor_quotient (SCM x, SCM y);
+SCM_API SCM scm_floor_remainder (SCM x, SCM y);
+SCM_API void scm_ceiling_divide (SCM x, SCM y, SCM *q, SCM *r);
+SCM_API SCM scm_ceiling_quotient (SCM x, SCM y);
+SCM_API SCM scm_ceiling_remainder (SCM x, SCM y);
+SCM_API void scm_truncate_divide (SCM x, SCM y, SCM *q, SCM *r);
+SCM_API SCM scm_truncate_quotient (SCM x, SCM y);
+SCM_API SCM scm_truncate_remainder (SCM x, SCM y);
+SCM_API void scm_centered_divide (SCM x, SCM y, SCM *q, SCM *r);