Other interns (2019):

- Namrata (CMI), LIP6, with Vincent Viallat Cohen-Addad.

May 2019 to July 2019. **Balasubramanian A.R.** (CMI) had an internship at LSV, ENS Paris-Saclay, under the supervision of Philippe Schnoebelen and Sylvain Schmitz. He developed length-function theorems for the finite sets of *d*-dimensional vectors of natural numbers, considering both the Hoare and the Smyth orderings for powersets. He also characterized the maximal length of controlled non-dominating sequences in the 2-dimensional case. In September 2019, Balasubramanian will start a PhD thesis in *cotutelle* between TU München and Université de Bordeaux, under the supervision of Javier Esparza and Igor Walukiewicz (LaBRI).

May 20 to July 27, 2019. **Mohit Kumar Gupta** (IIT Bombay) had an internship at LaBRI under the supervision of Nathanaël Fijalkow. He worked on the verification of neural networks. More precisely, he experimented using GAN (generative adversarial networks) to produce large test sets, and the impact of this usage on the verification of image classifiers. The results of this internship will be posted on ArXiv, and will then be submitted to a machine learning conference.

May 20 to July 20, 2019. **Ashwani Anand** (CMI) had an internship at LaBRI under the supervision of Jérôme Leroux and Nathanaël Fijalkow. He worked on Algorithms for solving games on graphs, using the newly introduced approach of separating automata. With his advisers, he showed that it yields conceptually simple and provably optimal algorithms for solving games with combination of winning objectives. This result will be posted on ArXiv, and will be submitted at a later stage.

May 14 to July 20, 2019. **Satyaprakash Nayak** (CMI) had an internship at LIS, Aix-Marseille University, under the supervision of Jean-Marc Talbot. He studied various classes of visibly pushdown automata in the perspective of minimization and canonization. He also worked on the relationship of these approaches with canonization algorithms for non-classical tree automata such as stepwise tree automata.

May 10 to July 20, 2019. **Ahad Mirza Baig** (CMI) had an internship at LaBRI under the supervision of Corentin Travers. The goal of this internship was twofold: 1/ designing concurrent data structures, such as counters and snapshot, with sublinear amortized complexity, pursuing he line of research initiated during Ahad’s previous stay at LaBRI (September 2018); 2/ designing new renaming algorithms for message passing system whose range of execution contexts lies between full synchrony and full asynchrony. For instance, one may aim for gracefully degrading algorithms, in which the range of new name is a function of the level of synchrony of the actual execution. Renaming has mainly been studied in the shared memory model. Little is known on renaming algorithms for message-passing systems, in which only the synchronous and the fully asynchronous (e.g., [ABD + 90]) models have been investigated. Ahad completed his M.Sc at CMI in 2019 and will start a PhD at IST Austria under the supervision of Dan Alistarh.

May 10 to July 20, 2019. **Ekanshdeep Gupta** (CMI) had an internship at LSV under the supervision of Alain Finkel. He worked on VASSs (vector addition systems with states). It is known that these systems are well-structured. Ekanshdeep is working on a characterization of the closely related well-structured counter machines.

May 2 to July 11, 2019. **Agnishom Chattopadhyay** (CMI) had an internship at LaBRI under the supervision of Anca Muscholl and Filip Mazowiecki. He worked on pumping lemmas for max-plus weighted automata, towards an extension of Mazowiecki’s and Riveros’s results presented at STACS 2018. The results of this internship will be submitted to a journal.

March 10 to July 10, 2019. **Amrita Suresh** (B.E. from BITS Goa, MPRI in 2018-2019) prepares her M.Sc. internship at LSV under the supervision of Alain Finkel. She studies *systems of communicating automata using FIFO channels*: the model is undecidable in general, and few decidable subclasses have been identified. Amrita is working on well-structured FIFO channels automata. In October 2019, Amrita Suresh will start a PhD at University Paris-Saclay (LSV) under the supervision of Alain Finkel, on the verification of FIFO machines.

February 20 to June 30, 2019. **K.S. Thejaswini** (M.Sc at CMI) visited LSV to work with Paul Gastin and Stefan Schwoon (and C. Aiswarya during her visits at LSV) on *the control problem for asynchronous automata*. This is a fundamental problem which was already extensively studied during the last 20 years and which is still open despite some recent advances. So far, we only know that the problem is decidable for some important special cases and there are no cases for which the problem is known to be undecidable. During this internship, the work focused first on understanding and implementing existing techniques. Then, we generalized some of the results to all regular winning conditions, applying abstractions based on semigroups. This allows in particular to take fairness into account.

September to December 2018. **Ritam Raha** (CMI) had his M.Sc internship at IRISA, under the joint supervision of Loïc Helouet and Nicolas Markey. He worked on *quantitative aspects of opacity against an active opponent*. In 2019, Ritam will start a PhD in *cotutelle* between Universiteit Antwerpen and Université de Bordeaux, under the joint direction of Guillermo Perez, Jérôme Leroux (LaBRI) and Nathanaël Fijalkow (LaBRI).

September to December 2018. **Ahad Mirza Baig** (CMI) had his M.Sc internship at LaBRI under the supervision of Alessia Milani. He worked to *design fault-tolerant and efficient algorithms to implement fundamental concurrent objects* (such as counters). More… Ahad returned to LaBRI in May 2019 for an internship with Corentin Travers. He completed his M.Sc at CMI, and will start a PhD in the fall of 2019 at IST Austria under the supervision of Dan Alistarh.

May 28 to July 27, 2018. **Rajarshi Roy** (CMI) was an intern at LSV, under the joint supervision of Benedikt Bollig (LSV) and Arnaud Sangnier (IRIF). He studied *learning algorithms for concurrent systems* modeled as product automata. Rajarshi completed his MSc at CMI and will start a PhD in 2019 at the Max Planck Institute for Software Systems, Kaiserslautern, under the direction of Daniel Neider.

May 22 to July 18 2018. **Suman Sadhukhan** (CMI) did an internship at LSV, ÉNS Paris-Saclay, under the joint supervision of Alain Finkel and Philippe Schnoebelen. He worked on *Minimal Coverability Set Algorithms over Petri Nets*. More… Suman started a Ph.D. at IRISA (SUMO team), Univ. Rennes, in October 2018, under the supervision of Nathalie Bertrand, Nicolas Markey and Ocan Sankur.

May 14 to July 13 2018. **Sriram Yenamandra** (IIT Bombay) had an internship at LSV, ENS Paris-Saclay, under the supervision of Laurent Doyen. He worked on *graph-planning problems with expected finite horizon and fixed variance*. More…

May to July 2018. **Adwait Godbole** (IIT Bombay) did an internship at IRISA under the supervision of Blaise Genest and Nathalie Bertrand (funded by the EQUAVE associated team). He studied population control. More…

May 2018 to November 2018. **Balasubramanian A.R.** (CMI) had his MSc internship at LaBRI, under the supervision of Igor Walukiewicz and Frédéric Herbreteau. He worked on decidability of *the consensus problem for the heard-of model of computation for distributed algorithms*. He completed his MSc thesis in the Spring of 2019, and will start a PhD thesis in *cotutelle* between TU München and Université de Bordeaux in September 2019 under the supervision of Javier Esparza and Igor Walukiewicz (LaBRI).

May 10 to July 16, 2018. **Aditya Raut** (CMI) had an internship at LIGM, Université Paris-Est Marne-la-Vallée, under Laurent Bulteau‘s and Mathias Weller‘s supervision. He joined the ongoing research efforts on the *Tree Containment* Problem, that asks whether a given phylogenetic tree is *contained* in a given phylogenetic network. This NP-hard graph problem has important applications in phylogenetics. Aditya’s work yielded contributions to an ongoing software package capable of analyzing parameters in phylogenetic networks, as well as a draft for a research paper that will improve known results for the *Cluster Containment *Problem, which is closely related to *Tree Containment*. In 2019, Aditya joined the PhD program at Carnegie Mellon University (Pittsburgh).

May 10 to June 30, 2018. **Malavika Mukundan** (CMI) had an internship at LIGM, Université Paris-Est Marne-la-Vallée, under the joint supervision of Éric Colin de Verdière and Stéphane Sabourau (LAMA). She worked on the topology and the geometry of triangulated surfaces and 3-manifolds, and in particular on algorithmic and geometric problems related to systolic geometry. She also attended a one-week school on *Low-dimensional geometry and topology: discrete and algorithmic aspects *in Paris. More… In 2018, Malavika went on to prepare a PhD at the University of Michigan, Ann Arbor.

May 7 to July 20 2018. **Suman Dutta** (IISER Bhopal) did an internship at LSV, ENS Paris-Saclay, under the joint supervision of Alain Finkel and Serge Haddad. He worked on *Sequential Recursive Petri Nets as WSTS*. We studied Recursive Petri nets which extend Petri nets and contain stack automata. We showed that Recursive Petri nets are well structured transition systems for a new ordering and then termination and coverability are decidable. In 2019, Suman completed his M.Sc. at IISER Bhopal and joined IIM Lucknow for a PhD.

May 7 to July 7, 2018. **Ashwani Anand** (CMI) had an internship at IRIF, Université Paris Diderot, under the joint supervision of Thomas Colcombet (IRIF) and Sylvain Schmitz (LSV). He worked on vector addition systems with a polynomial restriction on the size of reachable configurations, as recently studied by Jérôme Leroux. He considered how the notion extends in the case of branching or affine systems, and obtained refined bounds on the achievable degrees of the polynomials. In 2019 he had another internship at LaBRI with Jérôme Leroux and Nathanaël Fijalkow.

May 1 to July 27 2018. **Ritam Raha** (CMI) had an internship at LaBRI, under the joint supervision of Nathanaël Fijalkow and Vincent Penelle. He studied the *algorithmic properties of finitely ambiguous weighted automata*. In 2019, Ritam will start a PhD in *cotutelle* between Universiteit Antwerpen and Université de Bordeaux, under the joint direction of Guillermo Perez, Jérôme Leroux (LaBRI) and Nathanaël Fijalkow (LaBRI).

January 1 to April 30 2018. **Varun Ramanathan** (CMI) did his MSc internship at LaBRI, under the joint supervision of Diego Figueira and Pascal Weil. He worked on *synchronous relations*, a particular way of looking at transducers, and a logical framework to handle them. Varun returned to Université de Bordeaux in 2018 to start a PhD under the joint direction of Pascal Weil and Diego Figueira.

January 1 to June 15 2018. **Archit Chauhan** (CMI) did his MSc internship at CMI, under the joint supervision of Alain Finkel and M. Praveen. He worked on *Verifying flat FIFO systems through counter systems*. We showed how to associate a reversal-bounded counter system to a flat FIFO system, opening the way to verifying FIFO systems by using the existing verification tools for counter systems. Archit started a PhD in 2018 at CMI, under the supervision of Samir Datta.

May 2017 to July 2017, **Nisarg Patel** (CMI) was intern at IRIF, under the supervision of Ahmed Bouajjani and Constantin Enea. His work addressed the issues of *modeling and verifying asynchronous web applications*. More… After his internship, Nisarg Patel pursued work on this topic with his advisors, together with Madhavan Mukund (CMI), and completed his M.Sc. from CMI in 2018. He started a PhD with Thomas Wies at New York University in 2018.

May 16 to July 19 2017. **Ritam Raha** (CMI) had an internship at LSV, ENS Paris-Saclay, under Philippe Schnoebelen‘s supervision. He studied the *piecewise testable complexity of words* and its algorithmic evaluation. More… Ritam later had internships at LaBRI and at IRISA. In 2019, Ritam will start a PhD in *cotutelle* between Universiteit Antwerpen and Université de Bordeaux, under the joint direction of Guillermo Perez, Jérôme Leroux (LaBRI) and Nathanaël Fijalkow (LaBRI).

May 15 to July 28, 2017. **Debraj Chakraborty** (CMI) had an internship at LaBRI, Bordeaux, under the supervision of Hugo Gimbert. He worked on *asynchronous distributed games with causal memory*. More… Debraj started a PhD in 2018 at Université Libre de Bruxelles, under the supervision of Jean-François Raskin.

May 11 to July 13, 2017. **Umesh Kumar** (IIT Bombay) had an internship at LSV, ENS Paris-Saclay, under Paul Gastin‘s supervision. He studied the *robustness of timed automata* in topological semantics and various subclasses of updatable timed automata. More…

May 10 to July 14, 2017. **Kunal Mittal** (IIT Bombay) had an internship at LSV, ENS Paris-Saclay, under Alain Finkel‘s supervision. He studied *well-structured transition systems*, and particularly Petri Nets and their extensions with special reset arcs. More… In September 2019, he will join Princeton University for a PhD.

May 9 to July 13, 2017. **Aalok Thakkar** (CMI) had an internship at LSV, ENS Paris-Saclay, under Stefan Haar‘s supervision. He worked on the *semantics of mutation dynamics*. More… Aalok started a PhD in 2018 at University of Pennsylvania, under the direction of Rajiv Alur.

May 2 to July 13, 2017. **Thejaswini K S** (CMI) worked at LaBRI, Bordeaux, under the supervision of Frédéric Herbreteau and Igor Walukiewicz on *on-the-fly algorithms for reachability and safety games*. More… She went on to do a PhD (September 2019) at Warwick University, under the supervision of Marcin Jurdzinski.

May 2 to July 13, 2017. **A.R. Balasubramanian** (CMI) worked under the supervision of Nathalie Bertrand and Nicolas Markey at IRISA, in the research team SUMO, on the *verification of parametric-size networks* of identical components broadcasting messages to their neighbors. More… He later did his MSc thesis at LaBRI, Bordeaux and went on in 2019 to do a PhD in *cotutelle* between TU München and Université de Bordeaux, under the supervision of Javier Esparza and Igor Walukiewicz (LaBRI).

February 01 to May 15, 2017. **Adithya Murali** (BITS Pilani, Hyderabad) had an internship at LaBRI, Bordeaux, under the supervision of Géraud Sénizergues. He worked on the small category of *deterministic matrices*. More…