struct bounds
   πC_LB::Float64
   πC_UB::Float64
   πDER_LB::Float64
   πDER_UB::Float64
   s_LB::Float64
   s_UB::Float64
   τe_LB::Float64
   τe_UB::Float64
   τc_LB::Float64
   τc_UB::Float64
end
