This paper revisits a combinatorial structure called the large set of ordered design (LOD). Among others, we introduce novel Latin matching and prove that order n leads to an LOD(n−1, n, 2n−1); thus, obtain constructions for LOD(1, 2, 3), LOD(2, 3, 5), LOD(4, 5, 9). Moreover, show constructing is at least as hard Steiner system S(n−2, n−1, 2n−2); therefore, must be prime. We also some applicati...

In the crystal structure of the title compound, C(11)H(26)N(3) (+)·Cl(-)·C(4)H(4)N(4), the (2Z)-2,3-diamino-but-2-ene-dinitrile (Z-DAMN) mol-ecules are connected with the chloride ions via N-H⋯Cl hydrogen bonds, forming ribbons running along the a axis. The guanidinium ions are located in between the ribbons formed by Z-DAMN mol-ecules and chloride ions.