Fig. 3
From: The link between orthology relations and gene trees: a correction perspective
S represents the species tree and \(R^*\) the relation graph constructed from the sets W, Z, X and Y. The illustration is given for \(W =\{1,2,3,4,5,6\}\) and \(Z = \{\{1,2,3\}, \{2,3,4\}, \{3,5,6\}, \{4,5,6\}\}\). \(Z' = \{\{1,2,3\}, \{4,5,6\}\}\) is a subset of Z which is a partition of W. \(R'\) is the “corrected” relation graph corresponding to \(Z'\)