👉 The term "unijugous" is a mathematical concept in graph theory. It refers to a graph that has exactly one vertex of degree 1, and all other vertices have degree 2 or more. This concept was introduced by the Russian mathematician Ilya Propp in 1975. In graph theory, a "unijugous" graph is a graph with no isolated vertices (vertices with no neighbors) and every vertex having at least two adjacent edges. It is
