The interval number i(P) of a poset P is the smallest t such that P is a containment poset of sets that are unions of at most t real intervals. For the special poset Bn(k) consisting of the singletons and k-subsets of an n-element set, ordered by inclusion, i(B~(k))---min{k,nk + 1} if In~2-kl >~ n/2
First order properties of random posets
✍ Scribed by Tomasz Łuczak
- Publisher
- Springer Netherlands
- Year
- 1991
- Tongue
- English
- Weight
- 397 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0167-8094
No coin nor oath required. For personal study only.
✦ Synopsis
Let LB = s2(n, p) be a binary relation on the set [n] = { 1, ?, , n} such that Se(i, i) for every i and W(i,j) with probability p, independently for each pair i, j E [n], where i <j. Define < as the transitive closure of W and denote poset ([n], <) by R(n, p). We show that for any constant p probability of each first order property of R(n, p) converges as n + co.
📜 SIMILAR VOLUMES
This paper settles a conjecture made in (Li [2]) that, if (PC: ~ ~< 2) is an ANTI-perfect sequence in a connected caccc poset having no one-way infinite fence, then either there are ~ < 2 and x e Pe\~+l such that Pc(> x) and P~(<x) are both fixed point free (fpf), in which case P is also fpf, or P h