Vyhovs'ka I. Yu.
Ukr. Mat. Zh. - 2015. - 67, № 12. - pp. 1658-1666
The problem of shadow is solved. It is equivalent to the problem of finding conditions for a point to belong to a generalized convex hull of a family of compact sets.
Ukr. Mat. Zh. - 2011. - 63, № 4. - pp. 466-471
We establish some criteria of convexity of compact sets in the Euclidean space. Analogs of these results are extended to complex and hypercomplex cases.
Ukr. Mat. Zh. - 2008. - 60, № 5. - pp. 709–711
We establish an external criterion for the convexity of a domain of a Euclidean space.