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Witt equivalence of global fields. II: Relative quadratic extensions. (English) Zbl 0812.11025
Up to isomorphism the Witt ring $$W(K)$$ of a number field is uniquely determined by the following finite set $$S(K)$$ of invariants: degree of $$K$$, level of $$K$$, number of real places, number of dyadic places, degrees and levels of the dyadic completions. This paper continues the author’s paper in Commun. Algebra 19, 1125-1149 (1991; Zbl 0724.11020). It investigates the relative quadratic extensions $$E/K$$.
Reviewer: A.Pfister (Mainz)

##### MSC:
 1.1e+13 Quadratic forms over global rings and fields 1.1e+82 Algebraic theory of quadratic forms; Witt groups and rings
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