+ int index = reverse_variable_lookup_short (cat, subscript);
+
+ return cat->vp[index].iact->vars[0];
+}
+
+/* Return the interaction corresponding to SUBSCRIPT */
+const struct interaction *
+categoricals_get_interaction_by_subscript (const struct categoricals *cat, int subscript)
+{
+ int index = reverse_variable_lookup_short (cat, subscript);