Completing categorical algebras : Extended abstract

Let Σ be a ranked set. A categorical Σ-algebra, cΣa for C, for short, is a small category C equipped with a functor σC : C n each σ ∈ Σn , n ≥ 0. A continuous categorical Σ-algebra is a cΣa which C; has an initial object and all colimits of ω-chains, i.e., functors N each functor σC preserves colimits of ω-chains. (N is the linearly ordered set of the nonnegative integers considered as a category as usual.) We prove that for any cΣa C there is an ω-continuous cΣa C ω , unique up to equivalence, which forms a “free continuous completion” of C. We generalize the notion of inequation (and equation) and show the inequations or equations that hold in C also hold in C ω . We then find examples of this completion when – C is a cΣa of finite Σ-trees – C is an ordered Σ algebra – C is a cΣa of finite A-sychronization trees – C is a cΣa of finite words on A.4th IFIP International Conference on Theoretical Computer ScienceRed de Universidades con Carreras en Informática (RedUNCI

The Combinatorics of Iterated Loop Spaces

It is well known since Stasheff's work that 1-fold loop spaces can be described in terms of the existence of higher homotopies for associativity (coherence conditions) or equivalently as algebras of contractible non-symmetric operads. The combinatorics of these higher homotopies is well understood and is extremely useful. For $n \ge 2$ the theory of symmetric operads encapsulated the corresponding higher homotopies, yet hid the combinatorics and it has remain a mystery for almost 40 years. However, the recent developments in many fields ranging from algebraic topology and algebraic geometry to mathematical physics and category theory show that this combinatorics in higher dimensions will be even more important than the one dimensional case. In this paper we are going to show that there exists a conceptual way to make these combinatorics explicit using the so called higher nonsymmetric $n$-operads.Comment: 23 page