Finite Automata with Undirected State Graphs

  • Martin Kutrib
  • Andreas MalcherEmail author
  • Christian Schneider
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 10952)


We investigate finite automata whose state graphs are undirected. This means that for any transition from state p to q consuming some letter a from the input there exists a symmetric transition from state q to p consuming a letter a as well. So, the corresponding language families are subregular and, in particular in the deterministic case, subreversible. In detail, we study the operational descriptional complexity of deterministic and nondeterministic undirected finite automata. To this end, the different types of automata on alphabets with few letters are characterized. Then the operational state complexity of the Boolean operations as well as the operations concatenation and iteration is investigated, where tight upper and lower bounds are derived for unary as well as arbitrary alphabets under the condition that the corresponding language classes are closed under the operation considered.


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Copyright information

© IFIP International Federation for Information Processing 2018

Authors and Affiliations

  • Martin Kutrib
    • 1
  • Andreas Malcher
    • 1
    Email author
  • Christian Schneider
    • 1
  1. 1.Institut für InformatikUniversität GiessenGiessenGermany

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