Algorithm 1 Selecting epsilon stable clusters from the hierarchy

1.Initialize ${\delta }_{(.)}=1$ for all leaves 2. Do bottom-up from all leaves (excluding the root): 2.1. If $ES\left(C_i\right)>0$ or ${\delta }_{C_i}=0$, continue to next leaf 2.2. Else if $ES\left(C_i\right)=0$ and $ES\left(C_{PARENT\left(i\right)}\right)>0$, set ${\delta }_{PARENT\left(i\right)}=1$ and set ${\delta }_{(.)}=0$ for all nodes in $C_{PARENT\left(i\right)}$’s subtree