• DocumentCode
    1107556
  • Title

    Ambiguity in Graphs and Expressions

  • Author

    Book, Ronald ; Even, Shimon ; Greibach, Sheila ; Ott, Gene

  • Author_Institution
    IEEE
  • Issue
    2
  • fYear
    1971
  • Firstpage
    149
  • Lastpage
    153
  • Abstract
    A regular expression is called unambiguous if every tape in the event can be generated from the expression in one way only. The flow-graph technique for constructing an expression is shown to preserve ambiguities of the graph, and thus, if the graph is that of a deterministic automaton, the expression is unambiguous. A procedure for generating a nondeterministic automaton which preserves the ambiguities of the given regular expression is described. Finally, a procedure for testing whether a given expression is ambiguous is given.
  • Keywords
    Ambiguity of regular expressions, decidability of ambiguity, flow-graph algorithm, preservation of ambiguity of graphs, preservation of ambiguity of regular expressions.; Automata; Automatic testing; Books; Information science; Laboratories; Mathematics; Physics; Ambiguity of regular expressions, decidability of ambiguity, flow-graph algorithm, preservation of ambiguity of graphs, preservation of ambiguity of regular expressions.;
  • fLanguage
    English
  • Journal_Title
    Computers, IEEE Transactions on
  • Publisher
    ieee
  • ISSN
    0018-9340
  • Type

    jour

  • DOI
    10.1109/T-C.1971.223204
  • Filename
    1671797