 But this BIO interface also allows to approach logical considerations from a dialogical perspective, either by considering deduction as a very specialized social practice, or by putting Gentzen’s Natural Deduction or Sequent Calculus into a dialogical setting (French 2015; Dutilh Novaes &amp; French 2018; French 2021). Deduction in itself is considered as an essentially dialogical matter (Dutilh Novaes 2013; 2015; 2016; 2020), where the role of the interlocutor (the Opponent or Skeptic) has been “internalized” over time, in the sense that the deductive method has integrated its role, which is not apparent anymore (Dutilh Novaes 2015: 600). In this regard, when a mathematician or a logician spells out a proof, they adopt both roles, the proponent’s and the opponent’s. This is the idea behind the “Built-In Opponent” expression which was inspired by Göran Sundholm’s lectures and talks on assertion, by the year 2000, when suggesting the idea that elimination rules can be read as the moves of an opponent aimed at testing the thesis. Another work dealing with the connexion between Natural Deduction and the dialogical approach in the sense of tradition 1 is Rahman et al. (2009) which was also directly influenced by Sundholm’s suggestion, and where the branches in the inference rules are said to incarnate the choices of the players as they appear in the extensive form of a strategy. The BIO conception shares this inspiration but developed in its own, proper dialogical conception and its proper objectives.