“…There have been some arguments about the possibility of causing instability by doing this. This has attracted a lot of attention from the research community; see Van Assche et al, 1999;Santos and Mondié, 2000;Mondié and Santos, 2001;Van Assche et al, 2001;Engelborghs et al, 2001;Mirkin, 2003a;Michiels et al, 2003;Fattouh et al, 2001;Mondié and Michiels, 2003). It was proposed as an open problem in the survey paper (Richard, 2003).…”