\begin{gather}
    x_{k,r+1} \le x_{k,r},\quad \forall k \in K, \forall r \in R \setminus \{\hat{r}\},
    \label{eq:con_incremental} \\
    x_{k\hat{r}} = 0,\quad \forall k \in K,
    \label{eq:con_inexorable} \\
    \sum_{k \in K} \sum_{r \in R} c_{kr} x_{kr} \le f.
    \label{eq:con_resource_hi}
\end{gather}
