=====Distributive lattices with operators===== Abbreviation: **DLO** ====Definition==== A \emph{distributive lattice with operators} is a structure $\mathbf{A}=\langle A,\vee,\wedge,f_i\ (i\in I)\rangle$ such that $\langle A,\vee,\wedge\rangle$ is a [[distributive lattice]] $f_i$ is \emph{join-preserving} in each argument: $f_i(\ldots,x\vee y,\ldots)=f_i(\ldots,x,\ldots)\vee f_i(\ldots,y,\ldots)$ ==Morphisms== Let $\mathbf{A}$ and $\mathbf{B}$ be distributive lattices with operators of the same signature. A morphism from $\mathbf{A}$ to $\mathbf{B}$ is a function $h:A\rightarrow B$ that is a distributive lattice homomorphism and preserves all the operators: $h(f_i(x_0,\ldots,x_{n-1}))=f_i(h(x_0),\ldots,h(x_{n-1}))$ ====Examples==== Example 1: ====Basic results==== ====Properties==== ^[[Classtype]] |variety | ^[[Equational theory]] |decidable | ^[[Quasiequational theory]] | | ^[[First-order theory]] |undecidable | ^[[Locally finite]] |no | ^[[Residual size]] |unbounded | ^[[Congruence distributive]] |yes | ^[[Congruence modular]] |yes | ^[[Congruence n-permutable]] | | ^[[Congruence regular]] | | ^[[Congruence uniform]] | | ^[[Congruence extension property]] | | ^[[Definable principal congruences]] |no | ^[[Equationally def. pr. cong.]] |no | ^[[Amalgamation property]] |yes | ^[[Strong amalgamation property]] |yes | ^[[Epimorphisms are surjective]] |yes | ====Subclasses==== [[Bounded distributive lattices with operators]] [[Distributive lattice-ordered semigroups]] ====Superclasses==== [[Distributive lattices]] ====References==== [(Ln19xx> )]