See the example of Section II.3.30 in

<cite authors="Engel, Klaus-Jochen; Nagel, Rainer">_Engel, Klaus-Jochen; Nagel, Rainer_, [**One-parameter semigroups for linear evolution equations**](http://dx.doi.org/10.1007/b97696), Graduate Texts in Mathematics. 194. Berlin: Springer. xxi, 586 p. (2000). [ZBL0952.47036](https://zbmath.org/?q=an:0952.47036).</cite>