Logical Methods in Computer Science (Sep 2013)
Randomness extraction and asymptotic Hamming distance
Abstract
We obtain a non-implication result in the Medvedev degrees by studying sequences that are close to Martin-L\"of random in asymptotic Hamming distance. Our result is that the class of stochastically bi-immune sets is not Medvedev reducible to the class of sets having complex packing dimension 1.
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