Epimorphisms in Varieties of Subidempotent Rresiduated Structures

0538234 - ÚI 2022 RIV CH eng J - Journal Article
Moraschini, Tommaso - Raftery, J.G. - Wannenburg, J. J.
Epimorphisms in Varieties of Subidempotent Rresiduated Structures.
Algebra Universalis. Roč. 82, č. 1 (2021), č. článku 6. ISSN 0002-5240. E-ISSN 1420-8911
R&D Projects: GA MŠMT(CZ) EF17_050/0008361
EU Projects: European Commission(XE) 689176 - SYSMICS
Institutional support: RVO:67985807
Keywords : Epimorphism * Residuated lattice * Brouwerian algebra * Heyting algebra * De Morgan monoid * Esakia space * Substructural logic * Relevance logic * Beth definability
OECD category: Pure mathematics
Impact factor: 0.526, year: 2021
Method of publishing: Limited access
http://dx.doi.org/10.1007/s00012-020-00694-2

A commutative residuated lattice A is said to be subidempotent if the lower bounds of its neutral element e are idempotent (in which case they naturally constitute a Brouwerian algebra A-). It is proved here that epimorphisms are surjective in a variety K of such algebras A (with or without involution), provided that each finitely subdirectly irreducible algebra B∈ K has two properties: (1) B is generated by lower bounds of e, and (2) the poset of prime filters of B- has finite depth. Neither (1) nor (2) may be dropped. The proof adapts to the presence of bounds. The result generalizes some recent findings of G. Bezhanishvili and the first two authors concerning epimorphisms in varieties of Brouwerian algebras, Heyting algebras and Sugihara monoids, but its scope also encompasses a range of interesting varieties of De Morgan monoids.
Permanent Link: http://hdl.handle.net/11104/0316060