Kisoron-ml March 2018

4 participants
5 discussions

Prof. Helmut Schwichtenberg at NII Logic Seminar
by Makoto Tatsuta 26 Mar '18

26 Mar '18

Prof. Helmut Schwichtenberg at NII Logic Seminar Date: April 2, 2018, 14:00--16:00 Place: National Institute of Informatics, Room 1208 (12th floor) 場所: 国立情報学研究所 12階 1208室 (半蔵門線,都営地下鉄三田線・新宿線神保町駅または東西線竹橋駅より徒歩5分) (地図 http://www.nii.ac.jp/about/access/) Speaker: Helmut Schwichtenberg (Munchen University) Title: Logic for exact real arithmetic Abstract: Real numbers in the exact (as opposed to floating-point) sense can be given in different formats, for instance as Cauchy sequences (of rationals, with Cauchy modulus), or else as infinite sequences (streams) of (i) signed digits -1, 0, 1 or (ii) -1, 1, bot containing at most one copy of bot (meaning undefinedness), so-called Gray code (di Gianantonio 1999, Tsuiki 2002). We are interested in formally verified algorithms on real numbers given as streams. To this end we consider formal (constructive) existence proofs M and apply a proof theoretic method (realizability) to extract their computational content. We switch between different representations of reals by labelling universal quantifiers on reals x as non-computational and then relativising x to a predicate CoI coinductively defined in such a way that the computational content of x in CoI is a stream representing x. The desired algorithm is obtained as the extracted term of the existence proof M, and the required verification is provided by a formal soundness proof of the realizability interpretation. As an example we consider multiplication of reals. This is a joint work with Ulrich Berger, Kenji Miyamoto and Hideki Tsuiki. 問合せ先: 龍田真 (国立情報学研究所) e-mail: tatsuta(a)nii.ac.jp http://research.nii.ac.jp/~tatsuta

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名古屋ロジックセミナー (3/12) のお知らせ
by Takayuki Kihara 10 Mar '18

10 Mar '18

皆様名古屋大学の木原貴行です．以下の要領で名古屋ロジックセミナーを開催します．多数のご参加をお待ちしております．名古屋ロジックセミナー http://www.math.mi.i.nagoya-u.ac.jp/~kihara/logic-seminar.html 日時：3月12日 (月) 15:30〜場所：名古屋大学大学院情報学研究科棟 314室講演者：Vassilios Gregoriades (トリノ大学) 題目： The Preiss Separation Theorem uniformly アブストラクト： The typical example of a uniformity-type result in descriptive set theory is the Souslin-Kleene Theorem, which says that the separation property of the class of analytic sets can be witnessed by a recursive function in the codes. An important consequence of the latter is the extension of the result HYP = effectively bi-analytic, in all recursive Polish spaces. In this talk we present the uniform version of a separation result by Preiss that deals with the convex analytic subsets of the Euclidean space. We show that the separation can be realized by a HYP function in the codes. Similarly to the case of the Souslin-Kleene Theorem, we conclude that every HYP convex subset of the Euclidean space can be obtained from the class of HYP compact convex sets by taking HYP increasing unions and HYP intersections. -------- Takayuki Kihara Graduate School of Informatics, Nagoya University, Japan URL: http://math.mi.i.nagoya-u.ac.jp/~kihara/index-j.html Email: kihara(a)i.nagoya-u.ac.jp

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International Summer School on Proof Theory
by Norbert Preining 10 Mar '18

10 Mar '18

皆様アクセリア株式会社と北陸先端科学技術大学院大学のプライニングです。今年の9月に行う証明論理サマースクールとワークショップのお知らせです。重複して受け取られた場合はご容赦ください。よろしくお願いします。 ======================== 1st International Summer School on Proof Theory Ghent, September 2-5, 2018 http://www.proofsociety.org/summer-school-2018/ Workshop on Proof Theory Ghent, September 6-7, 2018 http://www.proofsociety.org/workshop-2018/ The 1st International Summer School for Proof Theory in Ghent is arranged under the auspices of The Proof Society, and is sponsored by the Kurt Gödel Society. The Proof Society has recently been formed to support the notion of proof in its broadest sense, through a series of suitable activities; to be therefore inclusive in reaching out to all scientific areas which consider proof as an object in their studies; to enable the community to shape its future by identifying, formulating and communicating its most important goals; to actively promote proof to increase its visibility and representation. The aim of the summer school is to cover basic and advanced topics in proof theory. The focus of the first edition will be on structural proof theory, ordinal analysis, provability logic, automated theorem proving, and philosophical aspects of proof. Other areas like reverse mathematics, proof mining, and proof complexity will be covered at the workshop, and in follow up summer schools. The intended audience is advanced master students, PhD students, postdocs and experienced researchers in mathematics, computer science and philosophy. The summer school is co-located with a workshop on proof theory in Ghent (6-7 September). The workshop will be the inaugural meeting of The Proof Society. Students are invited to apply with an informal abstract (1 page) to the poster session which will be held as part of the workshop. Scientific Programme ==================== The summer school will provide six courses: Cut Elimination by Matthias Baaz (TU Wien) Ordinals and their applications by Andreas Weiermann (Ghent University) Philosophy of Proof Theory by Carlo Nicolai (King's College London) Provability Logic by David Fernandez Duque (Ghent University) Proof Theory in Computer Science by Andrei Voronkov (University of Manchester) Programme Extraction by Monika Seisenberger (Swansea University) In addition there will be one special evening lecture: Selected topics from the Theory of Truth by Rafal Urbaniak (Ghent University) Registration ============ Information about registration will be available from the website soon. Programme Committee =================== Bahareh Afshari, University of Gothenburg Matthias Baaz, TU Wien Arnold Beckmann, Swansea University (Chair) Lev Beklemishev, Steklov Mathematical Institute Balthasar Grabmayr, Humboldt University Berlin Rosalie Iemhoff, Utrecht University Joost Joosten, University of Barcelona Antonina Kolokolova, Memorial University of Newfoundland Norbert Preining, Accelia Inc. Andreas Weiermann, Ghent University Local organizing committee ========================== Arnold Beckmann, Swansea University David Belanger, Ghent University David Fernandez-Duque, Ghent University Lenny Neyt, Ghent University Rafal Urbaniak, Ghent University Andreas Weiermann, Ghent University (Chair) -- PREINING Norbert http://www.preining.info Accelia Inc. + JAIST + TeX Live + Debian Developer GPG: 0x860CDC13 fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13

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Int. Workshop on External and Internal Calculi for Non Classical Logics (EICNCL 2018, Deadline for submission: 23 April 2018)
by Katsuhiko Sano 07 Mar '18

07 Mar '18

-------------------------------------------------------------------------------------- Call For Papers Int. Workshop on External and Internal Calculi for Non Classical Logics (EICNCL 2018) Oxford, UK, 19 July 2018 (affiliated with IJCAR 2018 in FLOC 2018) http://weic2018.loria.fr/ Deadline for submission: 23 April 2018 ---------------------------------------------------------------------- ------------------- A one day workshop on External and Internal Calculi for Non Classical Logics will be held the 19 July 2018 in conjunction with the IJCAR 2018 Conference during FLOC 2018 in Oxford, UK. The purpose of this workshop would be to discuss recent results on analytic (external or internal) calculi for non-classical logics like intuitionistic, modal, epistemic logics, conditional logics, substructural, resouce logics, and other logical systems. Among some key points we can mention the relationships between internal and external calculi for such logics and also their use for studying proof-search, automated deduction (proof-theory and implementation) and also logical properties like decidability, conservativity, axiomatisations and interpolation. The workshop is intended to provide a forum for discussion between researchers interested in topics including, but not limited to, the following areas: - External and internal calculi for non-classical logics - Relationships and embeddings (translations) between calculi, interactions between syntax and semantics - New calculi for studying problems like decidability, conservativity and interpolation - Proof-search and countermodel generation - Methodologies and tools for translations between calculi - Implementations of analytic calculi, proof assistants We envisage a range of perspectives: proof-theoretic foundations, including decidability and complexity; model-theoretic, including semantic foundations (e.g., new semantics), modelling and verification of programs and systems. SUBMISSIONS Researchers interested in presenting their works are invited to submit an extended abstract (up to 10 pages) through Easychair : https://easychair.org/conferences/?conf=eicncl2018 by 23 April 2018. Papers will be reviewed by peers, typically members of the Programme Committee. A Special Issue of a Journal on these topics is expected after the workshop. PROGRAM COMMITTEE J. Brotherston (University College, London, UK) A. Ciabattoni (TU Vienna, Austria - co-chair) D. Galmiche (Lorraine University, CNRS, LORIA, France - co-chair) R. Goré (Australian National University, Australia) D. Larchey-Wendling (Lorraine University, CNRS, LORIA, France) G. Metcalfe (University of Bern, Switzerland) S. Negri (University of Helsinki, Finland) N. Olivetti (LSIS, Aix-Marseille University, France - co-chair) J. Otten (University of Oslo, Norway) V. de Paiva (Nuance communications, USA) R. Ramanayake (TU Vienna, Austria - co-chair) K. Sano (Hokkaido University, Japan) L. Santocanale (LIF, Aix-Marseille University, France) S. Smets (ILLC, Amsterdam University, Netherlands) L. Vigano (King's College London, UK) IMPORTANT DATES Submission deadline: 23 April 2018 Notification to authors: 9 May 2018 Final versions due: 21 May 2018 Workshop date: 19 July 2018 Additional information will be available through WWW address: http://weic2018.loria.fr/ The workshop is co-organized by A. Ciabattoni, R. Ramanayake (TU Vienna), N. Olivetti (LSIS, Aix-marseille University) and D. Galmiche (LORIA - Lorraine University)

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名古屋ロジックセミナー (3/9) のお知らせ
by Takayuki Kihara 05 Mar '18

05 Mar '18

皆様名古屋大学の木原貴行です．以下の要領で名古屋ロジックセミナーを開催します．多数のご参加をお待ちしております．名古屋ロジックセミナー http://www.math.mi.i.nagoya-u.ac.jp/~kihara/logic-seminar.html 日時：3月9日 (金) 15:30〜場所：名古屋大学大学院情報学研究科棟 314室講演者：薄葉季路 (早稲田大学)　題目： Extendible cardinals and the mantle アブストラクト： Mantle は V のすべての ground model の共通部分として定義される inner model であるが、mantle 自身は ground model である必要はない。一方で、ある超巨大基数が存在するならば mantle 自身が ground model になることが知られている。本講演では、巨大基数の仮定を弱めて、 extendible cardinal の存在から mantle が ground model になることを証明する。 -------- Takayuki Kihara Graduate School of Informatics, Nagoya University, Japan URL: http://math.mi.i.nagoya-u.ac.jp/~kihara/index-j,html Email: kihara(a)i.nagoya-u.ac.jp

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Kisoron-ml March 2018