fact: Definition re_co_do (X Z : CSetoid) (f : CSetoid_fun X Z) : CSetoid_fun X (Build_SubCSetoid Z (fun y : Z => {x : X | f x[=]y})) := Build_CSetoid_fun X (Build_SubCSetoid Z (fun y : Z => {x : X | f x[=]y})) (Re_co_do X Z f) (Re_co_do_strext X Z f).
imports: CoRN.metrics.Prod_Sub