“…, (20) is held since the SMDs is in the sliding mode initially, and after some finite‐time , the system will be kept in the sliding mode again. However, it is noted that the counterpart of [33] may not be ensured, because its SMDs may not operate from the initial time due to the fact that the system may be not on the sliding surface initially, i.e. the SMDs will work after some finite‐time , and and may not always equal to zeros, which results in (20) may not be ensured in this way.…”