Resource bounded randomness and weakly complete problems
We introduce and study resource bounded random sets based on Lutz's concept of resource bounded measure [7, 8]. We concentrate on nc-randomness (c ⩾ 2) which corresponds to the polynomial time bounded (p-) measure of Lutz, and which is adequate for studying the internal and quantitative structu...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
1997
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| In: |
Theoretical computer science
Year: 1997, Volume: 172, Issue: 1, Pages: 195-207 |
| ISSN: | 1879-2294 |
| DOI: | 10.1016/S0304-3975(95)00260-X |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1016/S0304-3975(95)00260-X Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S030439759500260X 
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| Author Notes: | Klaus Ambos-Spies, Sebastiaan A. Terwijn, Zheng Xizhong |
| Summary: | We introduce and study resource bounded random sets based on Lutz's concept of resource bounded measure [7, 8]. We concentrate on nc-randomness (c ⩾ 2) which corresponds to the polynomial time bounded (p-) measure of Lutz, and which is adequate for studying the internal and quantitative structure of E = DTIME(2lin). However, we will also comment on E2 = DTIME(2pol) and its corresponding (p2-) measure. First we show that the class of nc-random sets has p-measure 1. This provides a new, simplified approach to p-measure 1-results. Next we compare randomness with genericity (in the sense of [2, 3]) and we show that nc + 1-random sets are nc-generic, whereas the converse fails. From the former we conclude that nc-random sets are not p-btt-complete for E. Our technical main results describe the distribution of the nc-random sets under p-m-reducibility. We show that every nc-random set in E has nκ-random predecessors in E for any k ⩾ 1, whereas the amount of randomness of the successors is bounded. We apply this result to answer a question raised by Lutz [10]: We show that the class of weakly complete sets has measure 1 in E and that there are weakly complete problems which are not p-btt-complete for E. |
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| Item Description: | Elektronische Reproduktion der Druck-Ausgabe 9. November 1999 Gesehen am 17.04.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1879-2294 |
| DOI: | 10.1016/S0304-3975(95)00260-X |