Residuated lattices do not have the amalgamation property
arXiv:2504.16111
Abstract
We show that the variety of residuated lattices does not have the amalgamation property, thereby settling a long-standing open problem. In addition, we show that the amalgamation property fails for several subvarieties, including idempotent residuated lattices, involutive residuated lattices, and (integral) distributive residuated lattices.
7 pages, 4 figures