Parallel and algebraic lambda-calculi in intuitionistic propositional logic

Abstract

We introduce a novel model that interprets the parallel operator, also present in algebraic calculi, within the context of propositional logic. This interpretation uses the category $\mathbf{Mag}_{\mathbf{Set}}$, whose objects are magmas and whose arrows are functions from the category $\mathbf{Set}$, specifically for the case of the parallel lambda calculus. Similarly, we use the category $\mathbf{AMag}^{\mathcal S}_{\mathbf{Set}}$, whose objects are action magmas and whose arrows are also functions from the category $\mathbf{Set}$, for the case of the algebraic lambda calculus. Our approach diverges from conventional interpretations where disjunctions are handled by coproducts, instead proposing to handle them with the union of disjoint union and the Cartesian product.