{ "id": "2008.03279", "version": "v1", "published": "2020-08-04T07:34:26.000Z", "updated": "2020-08-04T07:34:26.000Z", "title": "About finite posets R and S with \\# H(P,R) <= \\# H(P,S) for every finite poset P", "authors": [ "Frank a Campo" ], "comment": "24 pages, 7 figures. arXiv admin note: text overlap with arXiv:arXiv:1908.06897", "categories": [ "math.CO" ], "abstract": "Finite posets $R$ and $S$ are studied with $\\# {\\cal H}(P,R) \\leq \\# {\\cal H}(P,S)$ for every finite poset $P$, where ${\\cal H}(P,Q)$ is the set of order homomorphisms from $P$ to $Q$. It is shown that under an additional regularity condition, $\\# {\\cal H}(P,R) \\leq \\# {\\cal H}(P,S)$ for every finite poset $P$ is equivalent to $\\# {\\cal S}(P,R) \\leq \\# {\\cal S}(P,S)$ for every finite poset $P$, where ${\\cal S}(P,Q)$ is the set of strict order homomorphisms from $P$ to $Q$. A method is developed for the rearrangement of a finite poset $R$, resulting in a poset $S$ with $\\# {\\cal H}(P,R) \\leq \\# {\\cal H}(P,S)$ for every finite poset $P$. The results are used in constructing pairs of posets $R$ and $S$ with this property.", "revisions": [ { "version": "v1", "updated": "2020-08-04T07:34:26.000Z" } ], "analyses": { "subjects": [ "06A07", "06A06" ], "keywords": [ "finite poset", "strict order homomorphisms", "additional regularity condition", "equivalent", "rearrangement" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }