2 research outputs found
The Univalence Principle
The Univalence Principle is the statement that equivalent mathematical
structures are indistinguishable. We prove a general version of this principle
that applies to all set-based, categorical, and higher-categorical structures
defined in a non-algebraic and space-based style, as well as models of
higher-order theories such as topological spaces. In particular, we formulate a
general definition of indiscernibility for objects of any such structure, and a
corresponding univalence condition that generalizes Rezk's completeness
condition for Segal spaces and ensures that all equivalences of structures are
levelwise equivalences.
Our work builds on Makkai's First-Order Logic with Dependent Sorts, but is
expressed in Voevodsky's Univalent Foundations (UF), extending previous work on
the Structure Identity Principle and univalent categories in UF. This enables
indistinguishability to be expressed simply as identification, and yields a
formal theory that is interpretable in classical homotopy theory, but also in
other higher topos models. It follows that Univalent Foundations is a fully
equivalence-invariant foundation for higher-categorical mathematics, as
intended by Voevodsky.Comment: A short version of this book is available as arXiv:2004.06572. v2:
added references and some details on morphisms of premonoidal categorie