the rings considered in this article are commutative with identity $1neq 0$. by a proper ideal of a ring $r$,  we mean an ideal $i$ of $r$ such that $ineq r$.  we say that a proper ideal $i$ of a ring $r$ is a  maximal non-prime ideal if $i$ is not a prime ideal of $r$ but any proper ideal $a$ of $r$ with $ isubseteq a$ and $ineq a$ is a prime ideal. that is, among all the proper ideals of $r$,...

‎In 1970‎, ‎Menegazzo [Gruppi nei quali ogni sottogruppo e intersezione di sottogruppi massimali‎, ‎ Atti Accad‎. ‎Naz‎. ‎Lincei Rend‎. ‎Cl‎. ‎Sci‎. ‎Fis‎. ‎Mat‎. ‎Natur. 48 (1970)‎, ‎559--562.] gave a complete description of the structure of soluble $IM$-groups‎, ‎i.e.‎, ‎groups in which every subgroup can be obtained as intersection of maximal subgroups‎. ‎A group $G$ is said to have the $FM$...

Very little is known about the structure of intersection two $k$-generated monoids words, even for $k=3$. Here we investigate case $k$-maximal monoids, that is, whose basis cardinality $k$ cannot be non-trivially decomposed into at most words. We characterize in $3$-maximal monoids.

In this extended abstract we state some definitions and results from our earlier paper [2] and use these to characterize the class of edge-maximal graphs of branchwidth k. Similarly to the maximal graphs of treewidth k (the k-trees) they turn out to be a subclass of chordal graphs where every minimal separator has size k.

A subset of vertices of a graph G is k-independent if it induces in G a subgraph of maximum degree less than k. The minimum and maximum cardinalities of a maximal k-independent set are respectively denoted ik(G) and βk(G). We give some relations between βk(G) and βj(G) and between ik(G) and ij(G) for j 6= k. We study two families of extremal graphs for the inequality i2(G) ≤ i(G) + β(G). Finall...