Traversing a tree involves iterating over all nodes in some manner. The dedicated codice 96 function is specialized on iterating hash tables. Iterating an infinite number of times results in the Jerusalem cube. The Vector class in Java has two means for iterating over its elements. One example is Newton's method of iterating to a root of a nonlinear expression. Feedback is applied to the equilibration process iterating between router and microsimulator. For iterating the database, the Order function returns the next key to use. By iterating the weights are modified until the output error reaches an acceptable level. For example, iterating over a directory structure could be implemented with a visitor pattern. Iterating this construction, one gets eventually a field over which factors into linear factors. A quantum walk corresponds to iterating the shift and coin operators repeatedly. Iterating the process, one gets eventually the solutions of the initial problem. Check whether a point reached in iterating a pixel has been reached before. Iterating tetration leads to another operation, and so on, a concept named hyperoperation.