We construct a Π2 enumeration degree which is a strong minimal cover.

It has been known for more than 40 years that there are posets with planar cover graphs and arbitrarily large dimension. Recently, Streib and Trotter proved that such posets must have large height. In fact, all known constructions of such posets have two large disjoint chains with all points in one chain incomparable with all points in the other. Gutowski and Krawczyk conjectured that this feat...

An old question of Yates as to whether all minimal degrees have a strong minimal cover remains one of the longstanding problems of degree theory, apparently largely impervious to present techniques. We survey existing results in this area, focussing especially on some recent progress.

An equivalence graph is a vertex disjoint union of complete graphs. For a graph G, let eq(G) be the irdnimum number of equivalence subgraphs of G needed to cover all edges of G. Similarly, let cc(G) be the minimum number of complete subgraphs of G needed to cover all its edges. Let H be a graph on n vertices with ma,'dmal degree _~d (and minimal degree --~ 1), and let G=I~ be its complement. We...

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Composable safety certification envisions reuse of safety case argument-fragments together with safety-relevant components in order to reduce the cost and time needed to achieve certification. The argumentfragments could cover safety aspects relevant for different contexts in which the component can be used. Creating argument-fragments for the out-of-context components is time-consuming and cur...

In this paper a schema of graphical parameters is proposed. Based on the parameter integrity introduced by Barefoot, Entringer and Swart, members Ψ(G) of this schema have the general form Ψ(G) = min{ |S| + ψ(G − S) : S ⊂ V (G) }, where ψ(G) is another given graphical parameter. Examples include integrity, mean integrity, connectivity and vertex cover number. General results and bounds for the s...

We show that there exists a Martin-Löf random degree which has a strong minimal cover.