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AMPL > >Variables > >When certain variables are fixed, the nonlinear expressions in my model all become linear. Does AMPL consider my model to be linear in this case?

Yes, AMPL fixes the variables first, and then analyzes the model to determine whether it is linear. So if you make your model linear by fixing certain variables, you can direct AMPL to send the resulting problem instance to a linear solver for optimization.

Posted in: Variables