Real Algebraic and Analytic Geometry
Submission: 2005, February 21.
We consider sheaves of special groups (mainly over boolean spaces). They correspond to the sheaves of abstract Witt rings considered by Marshall, and with the help of his results we show that the so?called ``question 1" has a positive answer for spaces of orderings with a finite number of accumulation points. We also briefly present the behaviour of the boolean hull functor when applied to a sheaf of special groups.
Mathematics Subject Classification (2000): 11E81, 03C65.
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