A study of twelve specifications of the library problem

Twelve workshop papers [25] include an informal or formal specification of Kemmerer's library problem [28]. The specifications range from being knowledge-based to logic-based to Prolog-based. Though the statement of the informal requirements is short and "simple," twelve different approaches led to twelve different specifications. All twelve, however, address many of the same ambiguities and incompletenesses, which we describe in detail, present in the library problem. We conclude that for a given set of informal requirements, injecting domain knowledge helps to add reality and complexity to it, and formal techniques help to identify its deficiencies and clarify its imprecisions.