Figure 4
From: Evolution of orthologous tandemly arrayed gene clusters
Computation of the solution set at the internal node A of a species tree S by Multi-DILTAG. DILTAG is executed on each of the two branches (A
l
, A) and (A
r
, A), leading to the two pre-speciation sets 
and 
. In each branch, only minimum-cost paths are kept, which explains the removal of one gene order (indicated by a cross) from 
. The gene missing from the gene order of 
is reinserted in all possible positions (and all possible signs, which is not shown), and the resulting set is added to 
to form 
. Appropriate speciation edges are then added from the elements of 
to the elements of 
.