Robert P. Munafo, 2012 Apr 16.
Two mu-atoms are siblings if they have the same parent, that is, if they don't touch each other but they both touch the same larger mu-atom.
If the two siblings have no other siblings between them that are larger, then they are called neighbors.
various mu-atoms, some of which are siblings
Similarly, R2.1/3.2/3a, R2.1/3.1/2a and R2.1/3.1/3a are all siblings because they all have R2.1/3a as their parent. None of these is a sibling of any of the other labeled mu-atoms. For example R2.2/5.1/2a is also a tertiary continental mu-atom, but is not a sibling of R2.1/3.1/2a because it has a different parent.
revisions: 19971021 oldest on record; 20120416 add illustration
From the Mandelbrot Set Glossary and Encyclopedia, by Robert Munafo, (c) 1987-2017. Mu-ency index
This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2017 Feb 02. s.11