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تسجيل مستخدم جديدA Note on Computable Embeddings for Ordinals and Their Reverses
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We continue the study of computable embeddings for pairs of structures, i.e. for classes containing precisely two non-isomorphic structures. Surprisingly, even for some pairs of simple linear orders, computable embeddings induce a non-trivial degree structure. Our main result shows that although ${omega cdot 2, omega^star cdot 2}$ is computably embeddable in ${omega^2, {(omega^2)}^star}$, the class ${omega cdot k,omega^star cdot k}$ is emph{not} computably embeddable in ${omega^2, {(omega^2)}^star}$ for any natural number $k geq 3$.
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We study computable embeddings for pairs of structures, i.e. for classes containing precisely two non-isomorphic structures. Surprisingly, even for some pairs of simple linear orders, computable embeddings induce a non-trivial degree structure. Our m
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