By the linear algebraic representation of Petri nets, Desel introduced regularity property (Desel, 1992). Regularity implies a sufficient condition for a Petri net to be live and bounded. All the conditions checking the regularity of a Petri net are decidable in polynomial time in the size of a net (Desel and Esparza, 1995). This paper proves that regularity, liveness and boundedness can be pre...

This article provides an overview on regularity conditions for Fenchel duality in convex optimization. Our attention is focused, on the one hand, on three generalized interior-point regularity conditions expressed by means of the quasi interior and of the quasi-relative interior and, on the other hand, on two closednesstype conditions that have been recently introduced in the literature. We dis...

We prove a version of Szemerédi’s regularity lemma for subsets of a typical random set in F p . As an application, a result on the distribution of three-term arithmetic progressions in sparse sets is discussed.

Chvátal, Rödl, Szemerédi and Trotter [1] proved that the Ramsey numbers of graphs of bounded maximum degree are linear in their order. We prove that the same holds for 3-uniform hypergraphs. The main new tool which we prove and use is an embedding lemma for 3-uniform hypergraphs of bounded maximum degree into suitable 3-uniform ‘pseudo-random’ hypergraphs. keywords: hypergraphs; regularity lemm...

We prove a regularity lemma with respect to arbitrary Keisler measures μ on V , ν on W where the bipartite graph (V,W,R) is definable in a saturated structure M̄ and the formula R(x, y) is stable. The proof is rather quick, making use of local stability theory. The special case where (V,W,R) is pseudofinite, μ, ν are the counting measures, and M̄ is suitably chosen (for example a nonstandard mode...

In this note we discuss several combinatorial problems that can be addressed by the Regularity Method for hypergraphs. Based on recent results of Nagle, Schacht and the authors, we give here solutions to these problems. In particular, we prove the following: Let K (k) t be the complete kuniform hypergraph on t vertices and suppose an n-vertex k-uniform hypergraph H contains only o(n) copies of ...

The logarithmic-exponential (log-exp) function has been widely used in convex analysis and mathematical programming. This paper studies a natural generalization of the log-exp function. Certain necessary and sufficient conditions are obtained for establishing such a generalization. The derived sufficient conditions are explicitly expressed in terms of the first and second derivatives of the fun...

We investigate decompositions of a graph into a small number of low diameter subgraphs. Let P (n, 2, d) be the smallest k such that every graph G = (V, E) on n vertices has an edge partition E = E0 ∪ E1 ∪ . . . ∪ Ek such that |E0| ≤ 2n and for all 1 ≤ i ≤ k the diameter of the subgraph spanned by Ei is at most d. Using Szemerédi’s regularity lemma, Polcyn and Ruciński showed that P (n, 2, 4) is...

We prove a variant of the abstract probabilistic version of Szemerédi’s regularity lemma, due to Tao, which applies to a number of structures (including graphs, hypergraphs, hypercubes, graphons, and many more) and works for random variables in Lp for any p > 1. Our approach is based on martingale difference sequences.