If X and Y are spaces
with unique segments, an affine map from X into Y is a map which takes
segments into segments. The purpose of this paper is to give conditions on
spaces X and Y such that we can prove the following versions of the Open
Mapping and Closed Graph Theorems: (1) a continuous affine map of X
onto Y is open, and (2) an affine map of X onto Y with closed graph is
continuous.