3 papers
math.CT2000
Coherence, Homotopy and 2-Theories
Noson S. Yanofsky
2-Theories are a canonical way of describing categories with extra structure. 2-theory-morphisms are used when discussing how one structure can be replaced with another structure.…
math.CT1999
The Syntax of Coherence
Noson S. Yanofsky
This article tackles categorical coherence within a two-dimensional generalization of Lawvere's functorial semantics. 2-theories, a syntactical way of describing categories with st…
math.QA1998
Obstructions to Coherence: Natural Noncoherent Associativity
Noson S. Yanofsky
We study what happens when coherence fails. Categories with a tensor product and a natural associativity isomorphism that does not necessarily satisfy the pentagon coherence requir…