Addendum to: A Survey of Mu\vcnik and Medvedev Degrees
We include here some material that did not make its way into the published version (Bull. Symb. Log 18-2, June 2012, pp. 161-229, arXiv:1007.2376), in particular a proof of Theorem K to the effect that there is an initial segment of the strong degrees with dual theory IPC, the intuitionistic propositional calculus.
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