(* given a new coercion uri from src to tgt returns
* a list of (new coercion uri, coercion obj, universe graph)
*)
-let close_coercion_graph _ src tgt uri baseuri =
+let close_coercion_graph src tgt uri baseuri =
(* check if the coercion already exists *)
let coercions = CoercDb.to_list () in
let todo_list = get_closure_coercions src tgt uri coercions in