Setup a new external solver state for the eplex instance EplexInstance. The solver state will be associated with EplexInstance; EplexInstance must not already have a solver state associated with it. Once the solver state is setup, it can be invoked (e.g. via eplex_solve/1 or eplex_probe/2) to optimise the Objective function.
CostExpr is a linear expression (or quadratic if supported by the external solver).
Declaratively, this can be seen as a compound constraint representing all the individual linear constraints that have been set so far and are going to be set up later for EplexInstance. The invoking of this constraint is done explicitly by the user, usually via eplex_solve/1. Operationally, when the external solver is invoked, the delayed constraints posted to EplexInstance are collected and taken into account.
This is a simplified version of eplex_solver_setup/4, it is equivalent to calling eplex_solver_setup/4 with the following defaults:
eplex_solver_setup(Objective, _, [], [])