James Lee Hafner
Journal of Number Theory
Using 1947 work of Post showing that the word problem for semigroups is unsolvable, we explicitly exhibit an algebraic characterization of the bits of the halting probability Ω. Our proof closely follows a 1978 formulation of Post's work by M. Davis. The proof is self-contained and not very complicated.
James Lee Hafner
Journal of Number Theory
Ronen Feldman, Martin Charles Golumbic
Ann. Math. Artif. Intell.
Daniel J. Costello Jr., Pierre R. Chevillat, et al.
ISIT 1997
Ehud Altman, Kenneth R. Brown, et al.
PRX Quantum