👉 Contiguousness is a mathematical concept in set theory and graph theory. It refers to whether two sets are considered to be part of the same finite sequence if their elements are all identical. Imagine you have two sets A = {1, 2, 3, 4} and B = {2, 3, 5, 7}. If we concatenate these sets together (i.e., forming a new set C = {1, 2, 3, 2,