connected to connecting branch of b connecting-branch-of s iff b is connected to s, and there exists some tree-like structure t such that the mereological sum of b plus s is either the same as t or a branching-part-of t. In the tree T depicted in https://oborel.github.io/obo-relations/branching_part_of.png, B1 is connecting branch of S, and B1-1 as a connecting branch of B1. has connecting branch in branching relationship with