Comment on "Stability issues on Takagi-Sugeno fuzzy model-parametric approach" [with reply]

The stability conditions for Takagi-Sugeno fuzzy systems suggested in the above mentioned article by Lo-Chen (ibid. vol.7 (1999)) are shown by a counterexample not to be sufficient. In reply, Lo-Chen point out that the example also indicates the fuzzy stability problem is related to the premise part of fuzzy rules.