BTW Ipopt has special treatment of variables with the same upper and lower bounds. This option may be of interest, https://www.coin-or.org/Ipopt/documentation/node44.html#opt:fixed_variable_treatment
BTW Ipopt has special treatment of variables with the same upper and lower bounds. This option may be of interest, https://www.coin-or.org/Ipopt/documentation/node44.html#opt:fixed_variable_treatment