@article{Andreka:1995uh,
    Abstract = {We solve a problem of J{\'o}nsson {$[$}12{$]$} by showing that the class ℛof (isomorphs of) algebras of binary relations, under the operations of relative product, conversion, and intersection, and with the identity element as a distinguished constant, is not axiomatizable by a set of equations. We also show that the set of equations valid in ℛis decidable, and in fact the set of equations true in the class of all positive algebras of relations is decidable.},
    Author = {Andr{\'e}ka, H. and Bredikhin, D. A.},
    Date = {1995/12/01},
    File = {The equational theory of union-free algebras of relations - Andréka-Bredikhin1995\_Article\_TheEquationalTheoryOfUnion-fre.pdf},
    ISBN = {1420-8911},
    Journal = {algebra universalis},
    Number = {4},
    Pages = {516--532},
    Title = {The equational theory of union-free algebras of relations},
    URL = {https://doi.org/10.1007/BF01225472},
    Volume = {33},
    Year = {1995},
    bdsk-url-1 = {https://doi.org/10.1007/BF01225472},
    date-added = {2022-02-17 10:28:06 +0100},
    date-modified = {2022-02-17 10:28:07 +0100},
    id = {Andr{\'e}ka1995},
    doi = {10.1007/BF01225472}
}

@article{Andreka:1995uh, Abstract = {We solve a problem of J{\'o}nsson {$[$}12{$]$} by showing that the class ℛof (isomorphs of) algebras of binary relations, under the operations of relative product, conversion, and intersection, and with the identity element as a distinguished constant, is not axiomatizable by a set of equations. We also show that the set of equations valid in ℛis decidable, and in fact the set of equations true in the class of all positive algebras of relations is decidable.}, Author = {Andr{\'e}ka, H. and Bredikhin, D. A.}, Date = {1995/12/01}, File = {The equational theory of union-free algebras of relations - Andréka-Bredikhin1995_Article_TheEquationalTheoryOfUnion-fre.pdf}, ISBN = {1420-8911}, Journal = {algebra universalis}, Number = {4}, Pages = {516--532}, Title = {The equational theory of union-free algebras of relations}, URL = {https://doi.org/10.1007/BF01225472}, Volume = {33}, Year = {1995}, bdsk-url-1 = {https://doi.org/10.1007/BF01225472}, date-added = {2022-02-17 10:28:06 +0100}, date-modified = {2022-02-17 10:28:07 +0100}, id = {Andr{\'e}ka1995}, doi = {10.1007/BF01225472} }