It is proved that for every natural n ≥ 1, there exists a computable freely generated projective plane with computable dimension n. It is stated that the class of freely generated projective planes is complete with respect to degree spectra of automorphically nontrivial structures, effective dimensions, expansions by constants, and degree spectra of relations.
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(N. T. Kogabaev) Supported by the Grants Council (under RF President) for State Aid of Leading Scientific Schools (grant NSh-6848.2016.1) and by RFBR (projects No. 14-01-00376 and 13-01-91001-ANF_a).
Translated from Algebra i Logika, Vol. 55, No. 6, pp. 704-737, November-December, 2016.
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Kogabaev, N.T. Freely Generated Projective Planes with Finite Computable Dimension. Algebra Logic 55, 461–484 (2017). https://doi.org/10.1007/s10469-017-9418-9
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DOI: https://doi.org/10.1007/s10469-017-9418-9