=====Complemented lattices===== Abbreviation: **CdLat** ====Definition==== A \emph{complemented lattice} is a [[bounded lattices]] $\mathbf{L}=\langle L,\vee ,0,\wedge ,1\rangle $ such that every element has a complement: $\exists y(x\vee y=1\mbox{ and }x\wedge y=0)$ ==Morphisms== Let $\mathbf{L}$ and $\mathbf{M}$ be complemented lattices. A morphism from $\mathbf{L}$ to $\mathbf{M}$ is a function $h:L\rightarrow M$ that is a bounded lattice homomorphism: $h(x\vee y)=h(x)\vee h(y)$, $h(x\wedge y)=h(x)\wedge h(y)$, $h(0)=0 $, $h(1)=1$ ====Examples==== Example 1: $\langle P(S), \cup, \emptyset, \cap, S\rangle $, the collection of subsets of a set $S$, with union, empty set, intersection, and the whole set $S$. ====Basic results==== ====Properties==== ^[[Classtype]] |first-order | ^[[Equational theory]] |decidable | ^[[Quasiequational theory]] | | ^[[First-order theory]] |undecidable | ^[[Locally finite]] |no | ^[[Residual size]] |unbounded | ^[[Congruence distributive]] |yes | ^[[Congruence modular]] |yes | ^[[Congruence n-permutable]] |yes | ^[[Congruence regular]] |no | ^[[Congruence uniform]] |no | ^[[Congruence extension property]] |no | ^[[Definable principal congruences]] |no | ^[[Equationally def. pr. cong.]] |no | ^[[Amalgamation property]] | | ^[[Strong amalgamation property]] | | ^[[Epimorphisms are surjective]] | | ====Finite members==== $\begin{array}{lr} f(1)= &1\\ f(2)= &1\\ f(3)= &0\\ f(4)= &1\\ f(5)= &2\\ f(6)= &\\ f(7)= &\\ f(8)= &\\ \end{array}$ ====Subclasses==== [[Complemented modular lattices]] ====Superclasses==== [[Bounded lattices]] ====References==== [(Ln19xx> )]