Résumé
I report in this paper on my attempt to help students reflect on the axiomatic method and structuralist thinking in mathematics through a didactically-engineered activity (the theory of banquets, an invented structure simpler than group theory, but still quite rich semantically), as a lever to tackle the issue of the learning of abstract algebra. It sheds light into the cognitive processes involved in the conceptualization of an abstract algebraic structure, which are discussed within a semiotics framework. Empirical data show an insufficient syntax-semantic dialectic and mental processes based on the recognition of (visual) patterns.