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A Computably Categorical Structure Whose Expansion by a
Constant Has Infinite Computable Dimension

Status: published in the *Journal of
Symbolic Logic*, vol. 68 (2003), pp. 1199 - 1241.

Availability: DVI, PostScript, PDF

**Abstract.** Cholak, Goncharov, Khoussainov, and Shore
[J. Symbolic Logic 64 (1999) 13 - 37] showed that for each *k>0*
there is a computably categorical structure whose expansion by a
constant has computable dimension *k*. We show that the same is
true with *k* replaced by *omega*. Our proof uses a version
of Goncharov's method of left and right operations.

drh@math.uchicago.edu