In particular, he proved the unsolvability of the halting problem.    From Wordnik.com.  [Computability and Complexity] Reference

But she is one of the most explicit in noting its obscenity, its terribleness as well as its almost comedic unsolvability.    From Wordnik.com.  [Leave Them and Love Them] Reference

If one takes the uncertainty principle as a primitive and the unsolvability of the many-body problem as a given, it seems to me that microscopic irreversibility follows as the source of a quantum second law and the source of the arrow of time.    From Wordnik.com.  [Arrow of Time FAQ] Reference

Instead of referring to the "apparent unsolvability" of a choice between the quarto and the folio texts — and claiming that it is a "damaging ... breach" in "literary culture" — why not accept the two versions of Lear's last words, and the final scene more generally, as independent and equally valid alternatives?.    From Wordnik.com.  ['The Shakespeare Wars'] Reference