On Shokurov's Work Prelimiting Flips

The proof of the existence of a 3-fold log flip is presented that is based on the ideas of Shokurov's work Prelimiting Flips. On the one hand, this paper is an attempt to explain the ideas of that work through a specific example, and, on the other hand, to single out a specific result from this large work, a new simple proof of the existence of a 3-fold log flip.