In the figure of page 478 and 479 of the following paper one find that the author means that we have a (Canard) limit cycle. https://link.springer.com/chapter/10.1007/BFb0062381 On the other hand the system under consideration is $ $ \begin{cases} x’=y-x^2\ y’=\epsilon(a-x) \end{cases}$ $ It can be easily shown that the system has no limit cycle whenRead more