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Inverse Semigroups of Homeomorphisms are Hopfian

Published online by Cambridge University Press:  20 November 2018

Bridget B. Baird*
Affiliation:
University of Florida, Gainesville, Florida
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If X is a nonempty topological T1 space then the set of all homeomorphisms whose domains and ranges are closed subsets of X forms a semigroup under partial composition of functions. We call it IF(X). If, in a semigroup, every element a is matched with a unique element b such that aba = a and bab = b then the semigroup is an inverse semigroup (b is called the inverse of a and is denoted by a−1). We have that IF(X) is an inverse semigroup with the algebraic inverse of a map ƒ being just the inverse map ƒ-1. In this paper we examine epimorphisms from IF(X) onto IF(Y). The main theorem gives conditions under which an epimorphism must be an isomorphism.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1979

References

1. Baird, B. B., Epimorphisms of inverse semigroups of homeomorphisms between closed subsets, Semigroup Foru. 14 (1977), 161166.Google Scholar
2. Clifford, A. H. and Preston, G. B., The algebraic theory of semigroups, Math. Surveys of the Amer. Math. Soc. 7 Vol. 2 (Providence, 1967).Google Scholar
3. McAlister, D. B., Homomorphisms of semigroups of binary relations, Semigroup Foru. 3 (1971), 185188.Google Scholar
4. Thron, W. J., Lattice-equivalence of topological spaces, Duke Mathematical J. 29 (1962), 671679.Google Scholar