## Some Fundamental Algebraic Tools for the Semantics of
Computation Part 3. Indexed Categories

**R Burstall, J Goguen and A Tarlecki**
*Abstract:* This paper presents *indexed categories*,
which model uniformly defined families of categories, and suggests
that they are a useful tool for the working computer scientist. An
indexed category gives rise to a single *flattened* category
as a disjoint union of its component categories plus some
additional morphisms. Similarly, an indexed functor (which is a
uniform family of functors between the component categories)
induces a flattened functor between the corresponding flattened
categories. Under certain assumptions, flattened categories are
(co)complete if all their components are, and flattened functors
have left adjoints if all their components do. Several examples are
given.

*ECS-LFCS-89-90*

Previous |

Index |

Next