Problem. Does there exist a ZFC-example of a countably compact Hausdorff paratopological group which is not a topological group?

(The problem posed 27 May 2015 by Alexander Ravsky on page 9 of Volume 0 of the Lviv Scottish Book).

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    $\begingroup$ What, no prizes on this one? $\endgroup$ – Asaf Karagila Oct 20 '18 at 23:38
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    $\begingroup$ This is Problem 2.4.1 on p128 in the recent book Topological Groups and Related Structures by Arhangel'skij and Tkachenko. In the preceding section of the book it is shown that a regular Hausdorff countably compact paratopological group is a topological group. Also, a pseudocompact Hausdorff paratopological group is a topological group. Plus related results. Ravsky has published an example in 2003 under MA, hence the question. $\endgroup$ – Henno Brandsma Oct 21 '18 at 5:26

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