Full paper in PDF:
$%J. J. Madden and N. Schwartz, Separating ideals in dimension 2,
Rev. Mat. Univ. Complut. Madrid 10 (1997), supplementary, 217–240.
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Department of Mathematics Louisiana State University Baton Rouge LA 70803 — USA | Fakultät für Mathematik und Informatik Universität Passau Postfach 2540 94030 Passau — Germany |
Experience shows that in geometric situations the separating ideal associated with two orderings of a ring measures the degree of tangency of the corresponding ultrafilters of semialgebraic sets. A related notion of separating ideals is introduced for pairs of valuations of a ring. The comparison of both types of separating ideals helps to understand how a point on a surface is approached by different half-branches of curves.
1991 Mathematics Subject Classification: 13A18, 14P99.