sentences:  To search for an element in the tango tree, we simply simulate searching the reference tree.We start by searching the preferred path connected to the root, which is simulated by searching the auxiliary tree corresponding to that preferred path.If the auxiliary tree doesn't contain the desired element, the search terminates on the parent of the root of the subtree containing the desired element (the beginning of another preferred path), so we simply proceed by searching the auxiliary tree for that preferred path, and so forth.