no. 1
Local approximation of semialgebraic sets
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 5, Tome 1 (2002) no. 1, pp. 1-11.

Let A be a closed semialgebraic subset of euclidean space of codimension at least one, and containing the origin O as a non-isolated point. We prove that, for every real s≥1, there exists an algebraic set V which approximates A to order s at O. The special case s=1 generalizes the result of the authors that every semialgebraic cone of codimension at least one is the tangent cone of an algebraic set.

Classification : 14P10 
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     title = {Local approximation of semialgebraic sets},
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Ferrarotti, Massimo; Fortuna, Elisabetta; Wilson, Les. Local approximation of semialgebraic sets. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 5, Tome 1 (2002) no. 1, pp. 1-11. http://archive.numdam.org/item/ASNSP_2002_5_1_1_1_0/

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