18. A method of processing text intervals, comprising: extracting a first proposition from a first text interval; generating a first proposition tree from the first proposition, wherein the first proposition tree comprises a set of nodes and a set of edges, and wherein each edge includes a semantic relationship between nodes of the first proposition tree; determining a first similarity value between the first text interval and a second text interval based on a comparison of the first proposition tree and a second proposition tree corresponding to the second text interval, wherein the second text interval is different from the first text interval; determining a second similarity value between the second text interval and the first text interval; finding the second text interval redundant to the first text interval in response to the first and second similarity values each exceeding respective thresholds; and selectively outputting, using a processor, the second text interval based on at least one of the first similarity value and the redundancy finding.
20. The method of claim 18 , comprising: refraining from outputting redundant text intervals.