TY - JOUR ID - Hambardzumyan2016 LB - Hambardzumyan2016 AU - Hambardzumyan, Sasun AU - Mkrtchyan, Vahan V. AU - Musoyan, Vahe L. AU - Sargsyan, Hovhannes TI - The hardness of the independence and matching clutter of a graph ST - The hardness of the independence and matching clutter of a graph JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2016 VL - 36 IS - 3 SP - 375 EP - 397 DO - http://dx.doi.org/10.7494/OpMath.2016.36.3.375 UR - http://dx.doi.org/10.7494/OpMath.2016.36.3.375 AB - A clutter (or antichain or Sperner family) \(L\) is a pair \((V,E)\), where \(V\) is a finite set and \(E\) is a family of subsets of \(V\) none of which is a subset of another. Usually, the elements of \(V\) are called vertices of \(L\), and the elements of \(E\) are called edges of \(L\). A subset \(s_e\) of an edge \(e\) of a clutter is called recognizing for \(e\), if \(s_e\) is not a subset of another edge. The hardness of an edge \(e\) of a clutter is the ratio of the size of \(e\)'s smallest recognizing subset to the size of \(e\). The hardness of a clutter is the maximum hardness of its edges. We study the hardness of clutters arising from independent sets and matchings of graphs. KW - clutter KW - hardness KW - independent set KW - maximal independent set KW - matching KW - maximal matching SN - 1232-9274 ER -