Abstract
In this paper we prove that a point set in PG(2,q) meeting every line in 0, 1 or r points and having a unique tangent at each of its points is either an oval or a unital. This answers a question of Blokhuis and Szőnyi [1].
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Research was partially supported by OTKA Grants T 043758, F 043772; the preparation of the final version was supported by OTKA Grant T 049662 and TÉT grant E-16/04.
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Gács, A. On regular semiovals in PG(2,q). J Algebr Comb 23, 71–77 (2006). https://doi.org/10.1007/s10801-006-6029-2
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DOI: https://doi.org/10.1007/s10801-006-6029-2