Edited by Gerhard Heinzmann & Jean-Jacques Szczeciniarz

Jean-Jacques SZCZECINIARZ & Gerhard HEINZMANN Preface 3
Yacin HAMAMI Mathematical Rigor, Proof Gap and the Validity of Mathematical Inference 7
Ramzi KEBAILI La rigueur mathématique chez Henri Poincaré 27
Giorgio VENTURI Foundation of Mathematics between Theory and Practice 45
Hourya BENIS SINACEUR Facets and Levels of Mathematical Abstraction 81
Iris LOEB & Stefan ROSKI The Transition from Formula-Centered to Concept-Centered Analysis Bolzano’s Purely Analytic Proof as a Case Study 113
Emmylou HAFFNER D’un point de vue rigoureux et parfaitement geń eŕ al : pratique des matheḿ atiques rigoureuses chez Richard Dedekind 131
Paola CANTÙ The Right Order of Concepts: Grassmann, Peano, Gödel and the Inheritance of Leibniz’s Universal Characteristic 157
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Brice HALIMI Une nouvelle sémantique de l’itération modale 185