we would like to import cofe_solver only within the (sealed) module iProp_solution...

...but it does not work. Hu?

program_logic/model.v

 From iris.algebra Require Export upred.
 From iris.program_logic Require Export resources.
+(* We'd prefer to only import this in the sealed module, to make sure it does
+   not "escape". However, for some reason, that breaks importing model.v
+   elsewhere. *)
 From iris.algebra Require Import cofe_solver.
 
 (* The Iris program logic is parametrized by a locally contractive functor