Automorphisms of Steiner 2-designs S(2, 4, 37) are studied and used to find many new examples. Some of the constructed designs have S(2, 3, 9) subdesigns, closing the last gap in t...
The posets of dimension 2 are those posets whose minimal realizations have two elements, that is, which may be obtained as the intersection of two of their linear extensions. Gall...
Abstract. There are several well-known and important hamiltonian results for claw-free graphs but only a few are concerned with quasi-claw-free graphs. In this note, we provide a n...