A note on “automorphism groups of partial orders”
✍ Scribed by M.G. Stone
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 235 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
✦ Synopsis
We refer to articles by Bird [I] and Bird et al. [2] on automorphisms ol' posets. Let P, Q de-ote posets; P x Q is the Cartesian product with the lexicographic order and R&Q that same product with the "reverse" lexicographic order, viz. (p, -1) < (a', 9') iff 4 < q' or q = 4' and p *f p'. r(P) denotes the automorphism group of P, i.e. all order preserving maps of P onto P which have order preserving inverses. The wreath product r(Q) 1 r(P) is the group of permutations cf the csrtesian product of P with Q given by pairs (b, f) with b E T(P) and f~ (I'! uJ>)~ lvhich act on (p, q)~ PX Q by (b, f)(p, 9) = (b(p), f,(s)). The terminology and notatk3rl is essentially that found in [2], where the following rssult is established:
📜 SIMILAR VOLUMES
## Abstract A perfect edge colouring of a graph is defined by the property that all colour matchings are perfect matchings. Every edge‐coloured graph determines a group of graph automorphisms which preserve the colours of the edges. If the graph is connected, then this group of colour preserving au
Hy finding invariant embeddings of a partially ordered set X into the semigroups it is shown that the semigroup of order ideals of X. where the semigroup operation is set union, and the semigroup and semiring of order preserving maps from X into the positive cone D' of a partially tirdered integral
Perfectly orderable graphs were introduced by Chvfital in 1984. Since then, several classes of perfectly orderable graphs have been identified. In this paper, we establish three new results on perfectly orderable graphs. First, we prove that every graph with Dilworth number at most three has a simpl