“…In recent developments, ordered group invariants in C * -algebras and topological dynamics have been used to provide invariants of homeomorphisms of certain one-dimensional compact metrizable spaces ( [1], [2], [3], [6], [9], [10], [11], [16]). We can interpret these results as follows: the firstČech cohomology group of the space is given a preorder, and the isomorphism class of the resulting preordered group becomes an invariant of the homeomorphism class of the space.…”