The epis of the category of ordered algebras and -continuous homomorphisms
The equivalence of -groupoids and crossed complexes
The Euler characteristic of a category.
The exact sequence in the homology of groups with integral coefficients modulo associated to two normal subgroups
The existence and construction of Lax limits
The Exponential Law of Maps. II.
The extensive completion of a distributive category.
The Extraordinary Derived Category.
The first k-invariant, Quillen's space BG+ and the construction of Kann and Thurston.
The five- and nine-lemmas in P-semi-abelian categories.
The Formal Dimension of a Toplogical Space.
The frame of fibrewise closed nuclei
The free adjunction
The Frobenius relations meet linear distributivity.
The functor for the ring of integers of a number field
The fundamental groupoid scheme and applications
We define a linear structure on Grothendieck’s arithmetic fundamental group of a scheme defined over a field of characteristic 0. It allows us to link the existence of sections of the Galois group to with the existence of a neutral fiber functor on the category which linearizes it. We apply the construction to affine curves and neutral fiber functors coming from a tangent vector at a rational point at infinity, in order to follow this rational point in the universal covering of the affine...
The Galois-module structure of the space of holomorphic differentials of a curve.
The genesis of mathematical structures, as exemplified in the work of Charles Ehresmann
The Geometry of Self-adjunction
The Gersten conjecture for Witt groups in the equicharacteristic case.