Structurally complete finitary extensions of positive \L ukasiewicz logic

In this paper we study $\mathcal{MV}^+$, i.e. the positive fragment of {\L}ukasiewicz Multi-Valued Logic $\mathcal{MV}$. In particular we describe all the finitary extensions of $\mathcal{MV}^+$ that are structurally complete and all the axiomatic extensions of $\mathcal{MV}^+$ that are hereditarily structurally complete. Examples of hereditarily structurally complete finitary extensions and non hereditarily structurally complete finitary extensions are provided.