A note on initial Segments of the Enumeration Degrees
نویسندگان
چکیده
We show that no nontrivial principal ideal of the enumeration degrees is linearly ordered: In fact, below every nonzero enumeration degree one can embed every countable partial order. The result can be relativized above any total degree: If a,b are enumeration degrees, with a total, and a < b, then in the degree interval (a,b), one can embed every countable partial order.
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ورودعنوان ژورنال:
- J. Symb. Log.
دوره 79 شماره
صفحات -
تاریخ انتشار 2014