Residuated lattices
A residuated lattice is a structure L = (L,∨,∧,·,e,\,/) of type (2,2,2,0,2,2) such that
(L,·,e) is a
monoid,
(L,∨,∧) is a
lattice,
\ is the left residual of ·: y ≤ x\z ⇔ xy ≤ z, and
/ is the right residual of ·: x ≤ z/y ⇔ xy ≤ z.
Remark:
Let L and M be residuated lattices. A morphism from L to M is a function h : L→M that is a homomorphism: h(x∨y) = h(x)∨h(y) and h(x∧y) = h(x)∧h(y) and h(x·y) = h(x)·h(y) and h(x\y) = h(x)\h(y) and h(x/y) = h(x)/h(y) and h(e) = e.
| Classtype | Variety |
| Equational theory | Decidable [Hiroakira Ono, Yuichi Komori, Logics without the contraction rule, J. Symbolic Logic 50 (1985) 169--201 MRreview ZMATH] [implementation] |
| Quasiequational theory | Undecidable |
| First-order theory | Undecidable |
| Locally finite | No |
| Residual size | Unbounded |
| Congruence distributive | Yes |
| Congruence modular | Yes |
| Congruence n-permutable | Yes, n=2 |
| Congruence regular | No |
| Congruence e-regular | Yes |
| Congruence uniform | No |
| Congruence extension property | No |
| Definable principal congruences | No |
| Equationally definable principal congruences | No |
| Amalgamation property | |
| Strong amalgamation property | |
| Epimorphisms are surjective |