Module Gpr_interfaces.Sigs.Optimizer.Optimizer.Spec

module Spec: Gpr_interfaces.Specs.Optimizer  with module Eval = Eval.Spec

module Eval: Gpr_interfaces.Specs.Eval 
Derivatives always require evaluation functions
module Var: sig .. end
Input parameters that have derivatives
module Input: sig .. end
module Inputs: sig .. end