In a previous work, we have introduced weakening of Quillen model categories called weak categories. They still allow all the usual constructions category theory, but are easier to construct and in some sense better behaved. this paper continue develop their general theory by introducing combinatorial accessible We give simple necessary sufficient conditions under which such can be extended int...

Directed Algebraic Topology is a recent field, deeply linked with Category Theory. A ‘directed space’ has directed homotopies (generally non reversible), directed homology groups (enriched with a preorder) and fundamental n-categories (replacing the fundamental ngroupoids of the classical case). On the other hand, directed homotopy can give geometric models for lax higher categories. Applicatio...

We describe a construction that to each algebraically specified notion of higher-dimensional category associates a notion of homomorphism which preserves the categorical structure only up to weakly invertible higher cells. The construction is such that these homomorphisms admit a strictly associative and unital composition. We give two applications of this construction. The first is to tricateg...

We introduce flagged (∞, n)-categories and prove that they are equivalent to Segal sheaves on Joyal’s category Θn. As such, flagged (∞, n)-categories provide a model-independent formulation of Segal sheaves. This result generalizes the statement that n-groupoid objects in spaces are effective, as we explain and contextualize. Along the way, we establish a useful expression for the univalent-com...