Complex sentence: The tree-depth of a complete graph equals its number of vertices, for in this case the only possible forest "F" for which every pair of vertices are in an ancestor-descendant relationship is a single path.
Split into simpler sentences: The tree-depth of a complete graph equals its number of vertices. For, in this case, the only possible forest "F" for which every pair of vertices are in an ancestor-descendant relationship is a single path.