+ * Returns the current costs the copies are causing.
+ * The result includes inevitable costs and the costs
+ * of the copies regarding the current register allocation
+ * Uses the OU data structure
+ */
+int co_get_copy_costs(const copy_opt_t *co);
+
+/**
+ * Returns a lower bound for the costs of copies in this ou.
+ * The result includes inevitable costs and the costs of a
+ * minimal costs caused by the nodes of the ou.
+ * Uses the OU data structure
+ */
+int co_get_lower_bound(const copy_opt_t *co);
+
+
+
+
+
+/**
+ * Constructs another internal representation of the affinity edges
+ */
+void co_build_graph_structure(copy_opt_t *co);
+
+/**
+ * Frees the space used by the graph representation.
+ * Does NOT free the whole copyopt structure
+ */
+void co_free_graph_structure(copy_opt_t *co);
+
+/**
+ * Solves the problem using mixed integer programming
+ * @returns 1 iff solution state was optimal
+ * NYI