test.

Signed-off-by: parvy <pierre.arvy@artelys.com>

open-reac/README.md

@@ -213,6 +213,17 @@ Before to address the ACOPF (see [7](#7-alternative-current-optimal-power-flow))
   The DCOPF serves as a formal consistency check on the data.
 - The phases computed during the DCOPF resolution will be used as initial points for the ACOPF resolution.
 
+The DCOPF problem solved is :
+
+\begin{equation}
+\begin{tabular}{rl}
+minimize & $t$\\
+subject to & $f_0(x) - t \le 0$\\
+& $f_i(x) \le 0$, \quad $i=1, \dots, m$\\
+& $h_i(x) = 0$,   \quad $i=1, \dots, p$,\\
+\end{tabular}
+\end{equation}
+
 The DCOPF involves the following constraints:
 - `ctr_null_phase_bus_dc`, which sets the phase of the reference (refer to [5](#5-reference-bus--main-connex-component)) to 0.
 - `ctr_activeflow`, which defines the active power flowing through the branches of the network.