9. The system of claim 5 , wherein the matching module is configured to determine the first similarity value by determining a number of nodes and a number of edges that match between the first augmented proposition tree and the second proposition tree.
9. The system of claim 5 , wherein the matching module is configured to determine the first similarity value by determining a number of nodes and a number of edges that match between the first augmented proposition tree and the second proposition tree. 10. The system of claim 9 , wherein a first node in the first augmented proposition tree matches a second node in the second proposition tree in response to at least one word in, or associated with, the first node matching a word in, or associated with, the second node.