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Semiorderings and Witt rings

Published online by Cambridge University Press:  17 April 2009

Thomas C. Craven  and
Tara L. Smith
Thomas C. Craven
Affiliation:
Department of Mathematics, University of Hawaii, Honolulu, HI 96822–2273, United States of America e-mail: tom@math.hawaii.edu
Tara L. Smith
Affiliation:
Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH 45221–0025, United States of America e-mail: tsmith@math.uc.edu
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For a pythagorean field F with semiordering Q and associated preordering T, it is shown that the Witt ring WT (F) is isomorphic to the Witt ring W (K) whre K is a closure of F with respect to Q. For an arbitrary preordering T, it is shown how the covering number of T relates to the construction of WT (F).

Type
Research Article
Information
Bulletin of the Australian Mathematical Society , Volume 67 , Issue 2 , April 2003 , pp. 329 - 341
Copyright
Copyright © Australian Mathematical Society 2003

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