### `++udon`

    ++  udon                                                ::  abstract delta
              $:  p=umph                                    ::  preprocessor
                  $=  q                                     ::  patch
                  $%  [%a p=* q=*]                          ::  trivial replace
                      [%b p=udal]                           ::  atomic indel
                      [%c p=(urge)]                         ::  list indel
                      [%d p=upas q=upas]                    ::  tree edit
                  ==                                        ::
              ==                                            ::

See `%clay` doc