for a project that I work on, I need to know how many homomorphisms there are from one finite lattice with 0 and 1 to another. I remember that I already worked it out if one of them is the trivial lattice {0,1}.
Any ideas?
In detail:
Take two bounded lattices
$L_1,0_1,1_1,\vee_1,\wedge_1$ and $L_2,0_2,1_2,\vee_2,\wedge_2$
Let $f\in Hom(L_1,L_2)$, then
- $f(a\vee_1 b)=f(a)\vee_2 f(b)$
- $f(a\wedge_1 b) = f(a)\wedge_2 f(b)$
And $f \in Hom_{01}(L_1,L_2)$ if
- $f \in Hom(L_1,L_2)$ and
- $f(1_1)=1_2$
- $f(0_1)=0_2$
My question is:
What is $|Hom(L_1,L_2)|$ and $|Hom_{0,1}(L_1,L_2)|$ ?