LSDiff first extracts structural facts from each of the two program versions, then use set differencing to construct a list of changes, or deltas. Structural facts include subtyping facts about the class hierarchy as well as declarations of field and method class members. LSDiff also captures calls and field accesses relationships betwe a method and its target method or field. LSDiff infer rules u
![LSDiff](https://cdn-ak-scissors.b.st-hatena.com/image/square/120aa67ace637d12fdebeae73ea08421ca9433e9/height=288;version=1;width=512/http%3A%2F%2Fweb.cs.ucla.edu%2F~miryung%2Flsdiff-web%2Frule.jpg)