Computational complexity of functions

Leonid A. Levin
1996 Theoretical Computer Science  
Below is a translation from my Russian paper. I added references, unavailable to me in Moscow. Similar results have been also given in [9] (see also 161). Earlier relevant work (classical theorems like Compression, Speed-up, etc. ) was done in [ 15,13, 2, 1, 14, 7] .
doi:10.1016/0304-3975(95)00163-8 fatcat:26fnbywdi5d7fjba3jxa3xtnc4