I currently work on a large thesis, from which I derive some smaller publications such as papers. The work is in parallel. Often it happens that I copy some paragraphs from the thesis into a paper. Then I work on the paper, rewriting and reorganizing some of the copied text. When I work on the thesis again, I might want to integrate some of those changes. Of course this is a tedious process, because one has to compare sentence by sentence, in two texts that might be organized and structured very differently.

I'm looking for a software tool that can automatically find corresponding sentences in two texts and synchronize them forth and back, probably with me in the loop confirming each modification.