For posets P and Q, extremal saturation problems about weak strong P-free subposets of Q have been studied mostly in the case is Boolean poset Qn, all subsets an n-element set ordered by inclusion. In this paper, we study some instances problem with being grid, its connections to forbidden submatrix problem.

In this work, we introduce and study the forbidden-vertices problem. Given a polytope P and a subset X of its vertices, we study the complexity of linear optimization over the subset of vertices of P that are not contained in X . This problem is closely related to finding the k-best basic solutions to a linear problem. We show that the complexity of the problem changes significantly depending o...

in his seminal book on the historical periods of western attitudes toward death, philippe aries describes four consecutive periods through which these attitudes evolved and transformed. according to him, the historical attitudes of western cultures have passed through four major parts described above: “tamed death,” one’s own death,” “thy death,” and “forbidden death.” this paper, after explori...

We completely determine the complexity status of the dominating set problem for hereditary graph classes defined by forbidden induced subgraphs with at most five vertices.

A permutation is said to be –avoiding if it does not contain any subsequence having all the same pairwise comparisons as . This paper concerns the characterization and enumeration of permutations which avoid a set of subsequences increasing both in number and in length at the same time. Let be the set of subsequences of the form “ ”, being any permutation on . For ! the only subsequence in #" i...

We completely determine the complexity status of the 3-colorability problem for hereditary graph classes defined by two forbidden induced subgraphs with at most five vertices. © 2015 Elsevier B.V. All rights reserved.

Minimal forbidden factors are a useful tool for investigating properties of words and languages. Two factorial languages are distinct if and only if they have different (antifactorial) sets of minimal forbidden factors. There exist algorithms for computing the minimal forbidden factors of a word, as well as of a regular factorial language. Conversely, Crochemore et al. [IPL, 1998] gave an algor...