Arithmetical Reducibilities I
Arithmetical Reducibilities I
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算术约简 I
DOI:
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发表时间:
1971
期刊:
影响因子:
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通讯作者:
A. Selman
中科院分区:
文献类型:
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作者:
A. Selman
A 3D - reductibility relation is defined to be a transitive and reflexive relation & on sets of natural numbers, so that for every two sets A and B, A&B implies AeZ^. Two hierarchies of such reducibilities are studied, & , n < u), and n S , n < a). The reducibilities of each hierarchy have natural properties not possessed by the other. Each generalizes relative recursion; each S has the property that the class of £ sets is the for the S -degree structure, Various theorems concerning the structure of these reducibilities are proved.