The Brown-Golasinski model structure on strict ∞\infty-groupoids revisited

We prove that the folk model structure on strict $\infty$-categories transfers to the category of strict $\infty$-groupoids (and more generally to the category of strict $(\infty, n)$-categories), and that the resulting model structure on strict $\infty$-groupoids coincides with the one defined by Brown and Golasinski via crossed complexes.Comment: 24 pages, v2: generalization to strict $(\infty, n)$-categories adde

The control over personal data: True remedy or fairy tale ?

This research report undertakes an interdisciplinary review of the concept of "control" (i.e. the idea that people should have greater "control" over their data), proposing an analysis of this con-cept in the field of law and computer science. Despite the omnipresence of the notion of control in the EU policy documents, scholarly literature and in the press, the very meaning of this concept remains surprisingly vague and under-studied in the face of contemporary socio-technical environments and practices. Beyond the current fashionable rhetoric of empowerment of the data subject, this report attempts to reorient the scholarly debates towards a more comprehensive and refined understanding of the concept of control by questioning its legal and technical implications on data subject\^as agency

A Generic Information and Consent Framework for the IoT

The Internet of Things (IoT) raises specific issues in terms of information and consent, which makes the implementation of the General Data Protection Regulation (GDPR) challenging in this context. In this report, we propose a generic framework for information and consent in the IoT which is protective both for data subjects and for data controllers. We present a high level description of the framework, illustrate its generality through several technical solutions and case studies, and sketch a prototype implementation

Two polygraphic presentations of Petri nets

This document gives an algebraic and two polygraphic translations of Petri nets, all three providing an easier way to describe reductions and to identify some of them. The first one sees places as generators of a commutative monoid and transitions as rewriting rules on it: this setting is totally equivalent to Petri nets, but lacks any graphical intuition. The second one considers places as 1-dimensional cells and transitions as 2-dimensional ones: this translation recovers a graphical meaning but raises many difficulties since it uses explicit permutations. Finally, the third translation sees places as degenerated 2-dimensional cells and transitions as 3-dimensional ones: this is a setting equivalent to Petri nets, equipped with a graphical interpretation.Comment: 28 pages, 24 figure

The three dimensions of proofs

In this document, we study a 3-polygraphic translation for the proofs of SKS, a formal system for classical propositional logic. We prove that the free 3-category generated by this 3-polygraph describes the proofs of classical propositional logic modulo structural bureaucracy. We give a 3-dimensional generalization of Penrose diagrams and use it to provide several pictures of a proof. We sketch how local transformations of proofs yield a non contrived example of 4-dimensional rewriting.Comment: 38 pages, 50 figure

Orientals as free algebras

The aim of this paper is to give an alternative construction of Street's cosimplicial object of orientals, based on an idea of Burroni that orientals are free algebras for some algebraic structure on strict $\omega$-categories. More precisely, following Burroni, we define the notion of an expansion on an $\omega$-category and we show that the forgetful functor from strict $\omega$-categories endowed with an expansion to strict $\omega$-categories is monadic. By iterating this monad starting from the empty $\omega$-category, we get a cosimplicial object in strict $\omega$-categories. Our main contribution is to show that this cosimplicial object is the cosimplicial objects of orientals. To do so, we prove, using Steiner's theory of augmented directed chain complexes, a general result for comparing polygraphs having same generators and same linearized sources and targets.Comment: 28 page

La communauté des maîtres écrivains de Paris et l’enseignement de l’écriture sous l’Ancien Régime : dans la destinée de l’art calligraphique

A la fin du XVIe siècle naquit la communauté des maîtres écrivains jurés de Paris. Durant plus de deux cents ans, ses membres ont su dresser leur savoir distinctif sur une certaine forme d'écriture, purement artistique, tracée en respectant les règles sophistiquées de l'art calligraphique. Dans une société à dominante non-écrivante, cette habileté leur valut initialement, entre autres droits, celui, exclusif, de la tenue des écoles publiques d'écriture, pour qu 'enfin soient diffusés les fondements d'une écriture réglée dans sa perfection formelle. Or, les maîtres écrivains ne purent maintenir leur privilège dans l'enseignement, vite remis en cause dans le contexte d'alphabétisation croissante que connut l'ancien régime français et devant la lente diffusion, qui lui fut corrélative, d'une connaissance pratique et non plus esthétique de l'écriture. Entre ces deux réalités scripturales, la communauté a parcouru un itinéraire fort singulier, à contre courant de l'expansion du réseau scolaire et dont les faits marquants seront ici retracés.The formation of the “communauté des maîtres écrivains jurés de Paris” — an association of authorized scribes in Paris — dates to the end of the sixteenth century. For more than two hundred years its members stamped their distinctive mark on a certain form of writing, wholly artistic and drawn according to the carefully developed rules of calligraphic art. In a society where this form of communication was a rare skill, schools of writing, from which one sees the emergence of an approach to writing that was formulaic, formal and precise. The scribes could not, however, maintain their exclusive privileges as teachers for long. In the context of a slowly emerging ability to write — an important aspect of the ancien régime — this association found that the aesthetically pleasing kind of work which they endorsed competed with a more practical approach. Between these two ways of dealing with writing, the association committed itself to a single-minded policy in favour of artistry, an approach at odds with the expansion of scholarly activity. It is this conflict which the author reviews here