Аңдатпа
We study semantic and syntactic properties of spherical orders and their elementary theories, including nite and dense orders and their theories.It is shown that theories of dense n-spherical orders are countably categorical and decidable.The values for spectra of countable models of unary expansions of n-spherical theories are described.The Vaught conjecture is conrmed for countable constant expansions of dense n-spherical theories.