About me

Lukas Fleischer

Please do not send emails to spmtrp@lfos.de.

lfleischer@lfos.de

A917 6475 9326 B440

lfos

Short CV

Dec 2022–Nov 2023 Tech Lead Manager / Senior Software Engineer, Google Canada
Nov 2021–Nov 2022 Senior Software Engineer, Google Canada
Mar 2020–Oct 2021 Software Engineer, Google Canada
May 2019–Dec 2019 Postdoctoral Fellow, School of Computer Science, University of Waterloo
Aug 2015–Feb 2019 Ph.D. Computer Science, FMI, University of Stuttgart
Oct 2013–May 2015 M.Sc. Computer Science, University of Stuttgart
Oct 2010–Nov 2013 B.Sc. Computer Science, University of Stuttgart
Mar 1990 Born, Bietigheim-Bissingen

Publications

A list of my publications can also be found on DBLP.

Conference Articles

  1. Lukas Fleischer and Jeffrey Shallit. The State Complexity of Lexicographically Smallest Words and Computing Successors. DLT 2020.
  2. Lukas Fleischer and Manfred Kufleitner. Testing Simon's congruence. MFCS 2018.
  3. Lukas Fleischer. The Intersection Problem for Finite Semigroups. DLT 2018.
  4. Lukas Fleischer. On the Complexity of the Cayley Semigroup Membership Problem. CCC 2018.
  5. Lukas Fleischer and Manfred Kufleitner. The Intersection Problem for Finite Monoids. STACS 2018.
  6. Volker Diekert and Lukas Fleischer. Church-Rosser Systems, Codes with Bounded Synchronization Delay and Local Rees Extensions. WORDS 2017.
  7. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Finite Transformation Semigroups. CSR 2017.
  8. Lukas Fleischer and Manfred Kufleitner. Operations on Weakly Recognizing Morphisms. DCFS 2016.
  9. Lukas Fleischer and Manfred Kufleitner. Efficient Algorithms for Morphisms over Omega-Regular Languages. FSTTCS 2015.
  10. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. Block Products and Nesting Negations in FO2. CSR 2014.

Journal Articles

  1. Lukas Fleischer. The Cayley Semigroup Membership Problem. Theory of Computing. 2022.
  2. Lukas Fleischer and Jeffrey Shallit. Automata, Palindromes, and Reversed Subwords. Journal of Automata, Languages and Combinatorics, volume 26, numbers 3–4, pp 221–253. 2021.
  3. Lukas Fleischer and Jeffrey Shallit. Recognizing Lexicographically Smallest Words and Computing Successors in Regular Languages. International Journal of Foundations of Computer Science, volume 32, issue 6, pp 641–662. World Scientific, 2021.
  4. Lukas Fleischer. The Intersection Problem for Finite Semigroups. International Journal of Foundations of Computer Science, volume 31, issue 6, pp 827–842. World Scientific, 2020.
  5. Lukas Fleischer, Samin Riasat, and Jeffrey Shallit. New Bounds on Antipowers in Words. Inf. Proc. Letters, volume 164. 2020.
  6. Lukas Fleischer and Trevor Jack. The Complexity of Properties of Transformation Semigroups. International Journal of Algebra and Computation, volume 30, issue 3, pp 585–606. World Scientific, 2019.
  7. Lukas Fleischer and Manfred Kufleitner. The Complexity of Operations on Weakly Recognizing Morphisms. RAIRO-Theor. Inf. Appl., volume 53, number 1-2, pp 1–17. EDP Sciences, 2018.
  8. Lukas Fleischer and Manfred Kufleitner. Green's Relations in Deterministic Finite Automata. Theory of Computing Systems, volume 63, issue 4, pp 666–687. Springer, 2018.
  9. Lukas Fleischer, Manfred Kufleitner and Alexander Lauser. The Half-Levels of the FO2 Alternation Hierarchy. Theory of Computing Systems, volume 61, issue 2, pp 352–370. Springer, 2017.

Unpublished Papers

  1. Lukas Fleischer. Algorithms and Complexity Results for Finite Semigroups. PhD thesis, 2019.
  2. Lukas Fleischer. Efficient Membership Testing for Pseudovarieties of Finite Semigroups. Technical report, 2018.

Open Source Projects

Arch Linux

As an Arch Linux Developer and Trusted User, I am leading the development of the Arch User Repository web interface and maintaining the Arch Linux projects page as well as roughly 150 packages.

I am the author of aurdupes, a Python script that can be used to find duplicate packages in pacman databases and the Arch User Repository.

calcurse

I am the current maintainer of calcurse, a powerful command-line based calendar program.

Deprecated Projects

cdlib-eject was a lightweight C program to control Dacal CD Library II devices. It is no longer maintained.

Open Source Contributions

I occasionally contribute to other projects. Projects I have contributed to in the past include

  • alot, a terminal-based mail user agent,
  • arch-audit, an utility like pkg-audit for Arch Linux,
  • GNU automake, a tool to automate parts of the compilation process,
  • cgit, a hyperfast web frontend for Git repositories written in C,
  • OpenSMTPD spam filter integration,
  • the version control system Git,
  • jpeg-archive, a utility to compress JPEG images for long-term storage without sacrificing perceived visual quality,
  • libfaketime, a library that can be used to modify the system time for a single application,
  • the package manager pacman,
  • the password manager pass,
  • pygit2, which provides Python bindings for libgit2, and
  • xwax, an open-source Digital Vinyl System for Linux.