Goal:
    A : Type  P : list A → A → Type  b0 : All_fold P []
  ============================
   ({| pr1 := []; pr2 := b0 |} = {| pr1 := []; pr2 := All_fold_nil P |}
    → let H := CoreTactics.block in
      NoConfusionHom_All_fold A P [] (All_fold_nil P) b0
      → let H0 := CoreTactics.block in All_fold_nil P = b0)


DEBUG:Going to execute:
simplify * || simplify ?; cbv beta