Table 1 Commonly used variables and functions in this paper

$\mathcal{T}$

A set of phylogenetic trees

T _i

i th tree

m

Number of trees in $\mathcal{T}$

n

Number of taxa in each input tree

a _i

i th taxa

$\mathit{\text{freq}}(T,\mathcal{T})$

Frequency of the subtree T in $\mathcal{T}$

γ

Frequency cutoff

S _i

i th seed (each seed is a subtree of a tree in $\mathcal{T}$)

k

Size of a seed

c

Number of contractions used to create a seed