Recursively enumerable degrees and the conjugacy problem

Abstract

The principal result obtained is the theorem that for every recursively enumerable degree of unsolvability, there exists a finitely presented group whese conjugacy problem has that degree. (Parts I, II, III and IV.) In Part V this result is generalised to the theorem that certain complexes of recursively enumerable degrees of unsolvability may be obtained as the degrees of a complex of problems concerning conjugacy in a finitely presented group.