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机译:Free rectangular doppelsemigroups
Luhansk Taras Shevchenko Natl Univ, Dept Algebra & Syst Anal, Gogol Sq 1, UA-92703 Starobilsk, Ukraine;
Doppelsemigroup; free rectangular doppelsemigroup; free doppelsemigroup; interassociativity; doppelalgebra; semigroup; congruence;