Jeremy F. Alm, Robin Hirsch, Roger D. Maddux. There is no Finite-variable Equational Axiomatization of Representable Relation Algebras over Weakly Representable Relation Algebras. Rew. Symb. Logic, 9(3):511-521, 2016. [doi]
@article{AlmHM16,
title = {There is no Finite-variable Equational Axiomatization of Representable Relation Algebras over Weakly Representable Relation Algebras},
author = {Jeremy F. Alm and Robin Hirsch and Roger D. Maddux},
year = {2016},
doi = {10.1017/S1755020316000265},
url = {http://dx.doi.org/10.1017/S1755020316000265},
researchr = {https://researchr.org/publication/AlmHM16},
cites = {0},
citedby = {0},
journal = {Rew. Symb. Logic},
volume = {9},
number = {3},
pages = {511-521},
}