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@PHDTHESIS{AbuZaid:698352,
      author       = {Abu Zaid, Faried},
      othercontributors = {Grädel, Erich and Kuske, Dietrich},
      title        = {{A}lgorithmic {S}olutions via {M}odel {T}heoretic
                      {I}nterpretations},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Aachen},
      reportid     = {RWTH-2017-07663},
      pages        = {1 Online-Ressource (199 Seiten) : Illustrationen},
      year         = {2016},
      note         = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
                      University 2017; Dissertation, RWTH Aachen University, 2016},
      abstract     = {Model theoretic interpretations are an important tool in
                      algorithmic model theory. Their applications range from
                      reductions between logical theoriesto the construction of
                      algorithms for problems, which are hard in general but
                      efficiently solvable on restricted classes of structures,
                      like 3-Colorability on graphs of bounded treewidth. We
                      investigate this tool in three different areas of
                      Algorithmic Model Theory: automata-based decision procedures
                      for logical theories, algorithmic meta-theorems, and
                      descriptive complexity.One of the main focus points of this
                      dissertation are automata based presentations of infinite
                      objects, which are closely related to monadic second-order
                      interpretations over set variables. We introduce automatic
                      presentations with advice for several automata models. These
                      are presentations where the automata have access to some
                      fixed auxiliary information. We develop algebraic and
                      combinatorial tools, which enable us to prove that certain
                      structures cannot have an omega-automatic presentation with
                      advice. Our main result is that the field of reals is not
                      omega-automatic with any advice, which has been an open
                      problem since the introduction of omega-automatic
                      presentations.The result can also be understood as an answer
                      to a weakened version of a question posed by Rabin, namely
                      whether the field of reals is interpretable in the infinite
                      binary tree. Further, we consider uniformly automatic
                      classes of structures, which are classes generated by a
                      fixed presentation and a set of advices. Prototypic
                      examplesare the class of all finite graphs of treewidth
                      bounded by some constant, the torsion-free abelian groups of
                      rank 1, and the class of all countable linear orders.
                      Uniformly automatic presentations are also found in the
                      mechanics that build the foundation for several algorithmic
                      meta-theorems.We investigate the efficiency of this approach
                      by analysing the runtime of the generic automata-based model
                      checking algorithm in terms of the complexity of the given
                      presentation. We show that the runtime on a presentation of
                      the direct product closure is only one exponential higher
                      than the runtime on the presentation of the primal class. We
                      apply these findings to show that first-order model checking
                      is fixed parameter tractable on the classes of all finite
                      Boolean algebras and the class of all finite abelian groups.
                      In both cases the parameter dependence of the runtime is
                      elementary. The runtime which we achieve on these classes is
                      either provably optimal or outperforms the previously known
                      approaches. Furthermore, we show that the runtime of the
                      generic automata based algorithm for monadic second-order
                      model checking on graphs of treedepth at most h has a
                      (h+2)-fold exponential parameter dependence. This matches
                      the runtime of the best known algorithms for model checking
                      on these classes. In the last part of this dissertation we
                      turn our attention to logics with a build-in interpretation
                      mechanism. Polynomial time interpretation logic (PIL) is an
                      alternative characterisation of choiceless polynomial time
                      (CPT). CPT is currently considered the most promising
                      candidate for a logic capturing PTIME. We contribute to the
                      exploration of the expressive power of CPTby showing that
                      there is a CPT-definable canonisation procedure on classes
                      of structures with bounded abelian colours. A structure has
                      bounded abelian colours if it is of bounded colour class
                      size andthe automorphism group on every colour class is
                      abelian. Examples emerge from the classical examples that
                      separate fixed point logic with Counting from PTIME. The
                      CFI-construction of Cai, Fürer, and Immerman, as well as
                      the Multipedes of Blass, Gurevich, and Shelah have bounded
                      abelian colours. Consequently, the isomorphism problem on
                      these classes is solvable in CPT. For Multipedes this was an
                      open question. In fact, Blass, Gurevich, and Shelah
                      conjectured that the isomorphism problem for Multipedes
                      might not besolvable by a CPT procedure.},
      cin          = {117220 / 110000},
      ddc          = {510},
      cid          = {$I:(DE-82)117220_20140620$ / $I:(DE-82)110000_20140620$},
      typ          = {PUB:(DE-HGF)11},
      doi          = {10.18154/RWTH-2017-07663},
      url          = {https://publications.rwth-aachen.de/record/698352},
}