Objective.Functiontype t = private {e : Expr.t;Term that represents the objective function.
*)is_max : bool;Determine if we want to maximize or minimize this objective function.
*)index : index;Unique identifier from the input. This field is used as a priority index.
*)}Type of an objective function.
val pp : t Fmt.tpp ppf o prints the objective function o on the formatter ppf using the SMT-LIB format.