=====Bounded lattices===== Abbreviation: **BLat** ====Definition==== A \emph{bounded lattice} is a structure $\mathbf{L}=\langle L,\vee,0,\wedge,1\rangle$ such that $\langle L,\vee,\wedge\rangle $ is a [[lattice]] $0$ is the least element: $0\leq x$ $1$ is the greatest element: $x\leq 1$ ==Morphisms== Let $\mathbf{L}$ and $\mathbf{M}$ be bounded lattices. A morphism from $\mathbf{L}$ to $\mathbf{M}$ is a function $h:L\rightarrow M$ that is a 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: ====Basic results==== ====Properties==== ^[[Classtype]] |variety | ^[[Equational theory]] |decidable | ^[[Quasiequational theory]] |decidable | ^[[First-order theory]] |undecidable | ^[[Congruence distributive]] |yes | ^[[Congruence modular]] |yes | ^[[Congruence n-permutable]] |no | ^[[Congruence regular]] |no | ^[[Congruence uniform]] |no | ^[[Congruence extension property]] |no | ^[[Definable principal congruences]] |no | ^[[Equationally def. pr. cong.]] |no | ^[[Amalgamation property]] |yes | ^[[Strong amalgamation property]] |yes | ^[[Epimorphisms are surjective]] |yes | ^[[Locally finite]] |no | ^[[Residual size]] |unbounded | ====Finite members==== $\begin{array}{lr} f(1)= &1\\ f(2)= &1\\ f(3)= &1\\ f(4)= &2\\ f(5)= &5\\ \end{array}$ $\begin{array}{lr} f(6)= &15\\ f(7)= &53\\ f(8)= &222\\ f(9)= &1078\\ f(10)= &5994\\ \end{array}$ $\begin{array}{lr} f(11)= &37622\\ f(12)= &262776\\ f(13)= &2018305\\ f(14)= &16873364\\ f(15)= &152233518\\ \end{array}$ $\begin{array}{lr} f(16)= &1471613387\\ f(17)= &15150569446\\ f(18)= &165269824761\\ f(19)= &\\ f(20)= &\\ \end{array}$ [(HeiRei2002)] ====Subclasses==== [[Bounded modular lattices]] [[Complete lattices]] ====Superclasses==== [[Lattices]] ====References==== [(HeiRei2002> Jobst Heitzig and J\"urgen Reinhold, \emph{Counting finite lattices}, Algebra Universalis, \textbf{48}, 2002, 43--53 [[MRreview]] )]