Ciao,
prova con questo codice:
\begin{multline*}
\sum _{i=1} ^N \int\limits_0^{\overline t} \left\{ \left( – \dfrac{\vartheta R_i (t,e^{\bullet i})}{\vartheta e^i} + \dfrac{\vartheta D_i (t,e^{\bullet} I^{\bullet})}{\vartheta e^i} \right) (e^i (t) – e^{\bullet i} (t)) \right. \\
\shoveleft + \left( \dfrac{\vartheta C_i (t,I^{\bullet i})}{\vartheta I_i^i} + \dfrac{\vartheta D_i (t,e^{\bullet}, I^{\bullet})}{\vartheta I_i^i} \right) (I_i^i (t) – I_i^{\bullet i} (t)) \\
\shoveleft + \left. \sum _{j=1} ^N \left( \dfrac{\vartheta C_i (t,I^{\bullet i})}{\vartheta I_j^i} + \dfrac{\vartheta D_i (t,e^{\bullet}, I^{\bullet})}{\vartheta I_j^i} \right) (I_j^i (t) – I_j^{\bullet i} (t)) \right\} \, \text{d}t \geq 0 \\
\shoveleft \forall (e,I) \in K(e^\bullet, I^\bullet). \hfill
\end{multline*}
PS: meglio sostituire \vartheta con \partial
Stefano