Fig. 6.

Recursive definitions of Counters. For a species tree tripartition ($X|Y|Z$), and a gene tree node $w$, we compute the total hybrid weight of all quartets anchored at the species tripartition and with $w$ as the MRCA on the gene tree. Each solid colored path is weighed by the negative exponent of its length; each dashed path is weighted by one minus its support; each dotted path is weighted by its support. See also supplementary table S1, Supplementary Material online.