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This paper presents the Dexter hypertext reference model. The Dexter model is an attempt to capture, both formally and informally, the important abstractions found in a wide range of existing and future hypertext systems. The goal of the model is to provide a principled basis for comparing systems as well as for developing interchange and interoperability(More)
Even though many of the essential notions of hypertext were first contained in the description of a “memex,” written by Vannevar Bush in 1945 [Bus45], there are today only a few scattered implementations of hypertext, let alone any serious use of it in a CAD environment. In what follows, we describe what hypertext is all about. We describe a(More)
The query programs of certain databases report raw statistics for query sets, which are groups of records specified implicitly by a characteristic formula. The raw statistics include query set size and sums of powers of values in the query set. Many users and designers believe that the individual records will remain confidential as long as query programs(More)
Magpie is an interactive, integrate programming environment that supports the development of Pascal programs a powerful, single-user workstation. Incremental compilation techniques are used to provide quick feedback on static errors and to ensure that a program is always ready for execution even while it is being edited. Magpie performs syntax and static(More)
Programming environments support the creation, modification, execution and debugging of programs. The goal of integrating a programming environment is more than simply building tools that share a common data base and provide a consistent user interface. Ideally, the programming environment appears to the programmer as a single tool; there are no firewalls(More)
A database is compromised if a user can determine the data elements associated with keys which he did not know previously. If it is possible, compromise can be achieved by posing a finite set of queries over sets of data elements and employing initial information to solve the resulting system of equations. Assuming the allowable queries are linear, that is,(More)
A language-directed editor combines the text manipulation functions of a general-purpose editor with the syntax-checking functions of a compiler. It allows a user to create and modify a program in terms of its syntactic structure. The design of a user interface and an implementation for one such editor is described in language-independent terms. The design(More)