Refactor.

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

open-reac/README.md

@@ -333,8 +333,8 @@ The objective function also depends on parameters specified by the user (see [3.
 The `objective_choice` parameter modifies the values of penalties $\beta_1$, $\beta_2$, and $\beta_3$ in the objective function. 
 Specifically, if `objective_choice` takes on:
 - $0$, the minimization of active power production $\sum\limits_{i,g}\boldsymbol{P_{i,g}}$ is prioritized.
-- $1$, the minimization of $\sum\limits_{i} \boldsymbol{V_i}-(\rho V_i^{c,max} - (1-\rho)V_i^{c,min})^2$ is prioritized. The parameter $\rho$ 
-equals the configurable parameter `ratio_voltage_target`. 
+- $1$, the minimization of $\sum\limits_{i} \boldsymbol{V_i}-(\rho V_i^{c,max} - (1-\rho)V_i^{c,min})^2$ is prioritized ($\rho$ 
+equals the configurable parameter `ratio_voltage_target`). 
 - $2$, the minimization of $\sum\limits_{i} (\boldsymbol{V_i} - V_i^t)^2$ is prioritized.
 
 The objective function of the ACOPF is: