Category: AuthoringSystem
Organization: Department of Computer Science, Maryland
        University, College Park, MD, USA
Journal: Journal of Visual Languages and Computing
Abstract: The visual programming aspects of Trellis hypertext
        documents are described. A hypertext is a
        nonlinearly organized, browsable information
        structure. The importance of browsing distinguishes
        hypertext from other network information systems.
        The possible experiences a user may have when
        interacting with a hypertext are as important as its
        form. Further, these browsing semantics should be an
        inherent characteristic of a document, not of the
        implementation that allows browsing. In essence, a
        hypertext is an active entity that has a visible
        behavior, not a static entity that is manipulated by
        external means. The Trellis model employs the dual
        nature of Petri nets to formally express both
        aspects of a hypertext in one structure. A Petri net
        is a bipartite graph, so it captures the link
        structure of relationships among information
        elements. It is also an automaton, having an
        execution state and state transition rules, thereby
        formally capturing the interactions between reader
        and document. The authors define the temporal
        semantics of the Trellis model and illustrate them
        with a prototype hypertext system called alpha
        Trellis. This environment joins timed events and
        active computing engines into a dynamic, parallel
        browsing structure. In alpha Trellis, hypertext
        authoring is visual programming for a
        temporally-synchronized, visual outcome-temporal
        hyperprogramming.
Number: 3
Bibtype: Article
Author: P. D. Stotts
        R. Furuta
Pages: 237-53
Month: sep
Title: Temporal hyperprogramming
Year: 1990
Volume: 1
Keyword: computer graphics, formal logic, hypermedia, Petri
        nets, programming, user interfaces, visual
        programming, Trellis hypertext documents, browsable
        information structure, network information systems,
        Petri nets, bipartite graph, temporal semantics,
        alpha Trellis, timed events, active computing
        engines, parallel browsing structure, hypertext
        authoring, temporal hyperprogramming