On the antisymmetry of Galois embeddings
A Galois connection is a 'natural' way of relating two partially-ordered spaces (for example, semantic models of different expressive power). The most common form of Galois connection, which reflects one model being finer than the other, is that of a Galois embedding. This paper shows a published claim, 'two partially-ordered spaces related by a Galois embedding in each direction are isomorphic', to be false in general but true in the finite case. The proof we give provides an application of a 'disjoint from' calculus. (C) 2001 Elsevier Science B.V. All rights reserved.
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