* state that plus.ma needs nat and equality
*)
val load_deps_file: string -> (string * string list) list
-val write_deps_file: string -> (string * string list) list -> unit
+val write_deps_file: string option -> (string * string list) list -> unit
+(* FG ***********************************************************************)
+
+(* true if the argunent starts with a uri scheme prefix *)
+val is_uri: string -> bool