Figure 1
From: Parallelization of enumerating tree-like chemical compounds by breadth-first search order
Example of a family tree by BfsSimEnum and BfsMulEnum for C 2 O 2 H 2 and its separation by BfsEnumP1-3 with division depth 2. Molecular trees in gray color are regarded as invalid by the algorithms. It should be noted that hydrogen atoms are added as leaves at last.