Property information
x is a branching part of y if and only if x is part of y and x is connected directly or indirectly to the main stem of y
IAO 0000112
In the tree T depicted in https://oborel.github.io/obo-relations/branching_part_of.png, B1 is a (direct) branching part of T. B1-1, B1-2, and B1-3 are also branching parts of T, but these are considered indirect branching parts as they do not directly connect to the main stem S