Play audio slide show -- Keyboard shortcut: 'x'  Lecture overview -- Keyboard shortcut: 'u'  Previous page: Optional parameters of Scheme functions (1) -- Keyboard shortcut: 'p'  Next page: Closures -- Keyboard shortcut: 'n'  Lecture notes - all slides together  Annotated slide -- Keyboard shortcut: 't'  Textbook -- Keyboard shortcut: 'v'  Alphabetic index  Help page about these notes  Course home      Expressions, Types, and Functions - slide 41 : 46

Optional parameters of Scheme functions (2)
Keyword parameters is a good alternative to optional parameter lists in case many, 'unordered' parameters need to passed to a function