Figure 2 shows the three tree span schemes explored in <cite>Yang et al (2006)</cite> : MinExpansion (only including the shortest path connecting the anaphor and the antecedent candidate), Simple-Expansion (containing not only all the nodes in Min-Expansion but also the first level children of these nodes) and Full-Expansion (covering the sub-tree between the anaphor and the candidate), such as the sub-trees inside the dash circles of Figures 2(a) , 2(b) and 2(c) respectively.