9. The text processing apparatus according to claim 8 , wherein the descriptive content determination unit derives, based on the result of the determination by the segment determination unit, an extent to which the content of the homogeneous segment is included in the second text corresponding to the other first text which includes the homogeneous segment, further derives, based on the derived extent, a degree to which each segment constituting the first text which is set as the analysis target should be described in the second text corresponding to the first text which is set as the analysis target, and performs the determination using the degree.
8. The text processing apparatus according to claim 1 , wherein the segment determination unit includes an inclusion determination unit and a homogeneous segment specification unit, the inclusion determination unit determines, for the plurality of segments respectively constituting all of the first texts, whether a content of each segment is included in the second text corresponding to the first text which includes the segment, and the homogeneous segment specification unit, by contrasting each of the plurality of segments constituting the first text which is set as the analysis target and a segment that is determined by the inclusion determination unit to be included in the second text and that is included in another first text, specifies a segment similar to any of the plurality of segments constituting the first text which is set as the analysis target, and sets the specified segment as a homogeneous segment.