Names of design patterns appear in small capitals: e.g., ADAPTER. Page numbers in bold indicate the definition of a term. Numbers in italics indicate a diagram for the term. Letters after a diagram's page number indicate the kind of diagram: a "c" denotes a class diagram, an "i" denotes an interaction diagram, and an "o" denotes an object diagram. For example, 88co means that a class and object diagram appears on page 88.

U

undo/redo 59-60, 62-64, 235, 238, 283, 287

avoiding error accumulation during 239

Unidraw

use of ADAPTER 143

use of CHAIN OF RESPONSIBILITY 232

use of COMMAND 232, 242

use of FACTORY METHOD 111

use of ITERATOR 270

use of MEDIATOR 282

use of MEMENTO 289

use of OBSERVER 303

use of PROTOTYPE 126

use of STATE 313

UnsharedConcreteFlyweight

participant of Flyweight 199

updates

encapsulating complex 299

limiting unexpected 296

protocol for in OBSERVER 296

triggering 297