@misc{Seda_N._Manukian_On, author={Seda N. Manukian}, howpublished={online}, publisher={НАН РА}, abstract={The notions of positive and strongly positive arithmetical set are considered in ([1]-[3] ). It is noted in [3] that the transitive closure of any 2-dimensional strongly positive set is primitive recursive. In this article a more strong statement is proved: the transitive closure of any 2-dimensional strongly positive set is defined by an arithmetical formula in the signature (0,=, < ,S), where S(x)=x+1.}, type={Հոդված}, title={On Transitive Closures of Two-dimensional Strongly Positive Arithmetical Sets}, keywords={Elementary mathematics; Arithmetic, Mathematics, Algorithm}, }