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a b s t r a c tIn this paper we study structural properties of n-c. e. Q -degrees. Two theorems contain results on the distribution of incomparable Q -degrees. In another theorem we prove that every incomplete Π 0 2 Q -degree forms a minimal pair in the c. e. degrees with a ∆ 0 2 Q -degree.In a further theorem it is proved that there exists a c. e. Q -degree > 0 that is not half of a minimal pair in the c. e. Q -degrees.Crown (M.M. Arslanov), ilnurb@yandex.ru (I.I. Batyrshin), r.omanadze@math.sci.tsu.ge (R.Sh. Omanadze).

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