Accepting Normalization via Markov Magmoids
Elena Di Lavore, Mario Román
TL;DR
This work develops a synthetic, category-free approach to normalization in probabilistic semantics by introducing distributive sesquilaws, which capture multiplicativity up to an idempotent and justify a non-associative yet structurally rich normalization magmoid. It shows that normalized channels form a unital magmoid equipped with a monoidal structure and interacts with subdistributions via a distributive sesquilaw, yielding an action of Subd on Norm and a coherent theory of guarded choice through tricocycloids. The paper also clarifies the relation between normalized kernels and stochastic relations, arguing that stochastic relations are best modeled as a magmoid rather than a category, with support providing a morphism to May-Must and Dijkstra-type relation frameworks. Overall, it provides a unifying algebraic framework that captures normalization, guarded choice, and stochastic-relational analogies, connecting Markov-cat like semantics with relational abstractions. This advances probabilistic programming semantics by offering a principled way to reason about normalization without forcing strict categorical associativity.
Abstract
Normalization of probability distributions is not a distributive law. We introduce distributive sesquilaws to abstract normalization and, from their axioms, we derive some of its properties. In particular, normalized channels form a unital magmoid with an action of the category of subdistributions; its possibilistic analogue is the action from may-must relations into the category of relations. We argue that the magmoid of normalized channels is the stochastic analog of the category of relations.
