“…Note that this process is different from (actually simpler than) Pistorius' doubly reflected process of [34], since here the boundary behaviour at 0 is not reflection, and is also different from Lambert's [28] process confined in a finite interval (conditioned not to exit (0, b)). The discussion of these three cases is connected to the discussion in [10] and [27,Remark 3.3], which distinguish three types of exit at a boundary (A) continuously, (B) by a jump or (C) not at all (while preserving self-similarity of the process). In our context (two boundaries, self-similarity being meaningless on an interval, but re-entry being allowed), Lambert studies (C,C) exits from (0, b), no entry needed, Pistorius studies the (A,B) exit (A,A) entrance, and we find (A,B) exit (B,A) entrance.…”