Correspondence: Reply to Comments on a simplified analytical stability test for systems with delay

We wish to thank Dr. N. MacDonald for his interest in our paper [A]. We agree with Dr. MacDonald [B] that as an alternative way to deal with stability, negative values of the parameter T could also be considered. However, we disagree with his comment that our method, which considers only non-negative T, is deficient in any way. Indeed, our method suffices to deal with the two examples mentioned in Reference B as will be explained later on. To substantiate our claim, we present the following fact.