Frank a Campo

activity

20182024

most citedExponential functions of finite posets and the number of extensions with a fixed set of minimal points

5 citations · 11 across the 11 of their papers we have counts for

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Showing 2021Show all

5 papers · 1 filter

math.CO2021

Crowns as retracts

Frank a Campo

We investigate crowns as retracts of finite posets. We define a multigraph $F (P)$ reflecting the network of so-called improper 4-crowns contained in the extremal points…

math.CO2021

About posets for which no lower cover or no upper cover has the fixed point property

Frank a Campo

For a finite non-empty set $X$ , let $P (X)$ denote the set of all posets with carrier $X$ , ordered by inclusion of their partial order relations. We investigate propertie…

math.CO2021★ 2 cited

The fixed point property of a poset and the fixed point property of the poset induced by its extremal points

Frank a Campo

For a connected finite poset $P$ , let $E (P)$ be the poset induced by the extremal points of $P$ . We show that the fixed point property of $E (P)$ implies the fixed point property of…

math.CO2021

A generalization of a theorem of Erné

Frank a Campo

Let $X$ be a finite set, $Z \subseteq X$ and $y \in / X$ . Marcel Erné showed in 1981, that the number of posets on $X$ containing $Z$ as an antichain equals the number of posets $…

math.CO2021

A recursive approach for the enumeration of the homomorphisms from a poset $P$ to the chain $C_{3}$

Frank a Campo

Let $H (P, C_{3})$ be the set of order homomorphisms from a poset $P$ to the chain $C_{3} = 1 < 2 < 3$ . We develop a recursive approach for the calculation of the cardinality of $…

Crowns as retracts

About posets for which no lower cover or no upper cover has the fixed point property

The fixed point property of a poset and the fixed point property of the poset induced by its extremal points

A generalization of a theorem of Erné

A recursive approach for the enumeration of the homomorphisms from a poset P to the chain C3​

A recursive approach for the enumeration of the homomorphisms from a poset $P$ to the chain $C_{3}$