(* the index of the last created meta *)
val maxmeta: unit -> int
+(* Bad, this should be made functional and put in the status! *)
+val pushmaxmeta: unit -> unit
+val popmaxmeta: unit -> unit
+
(* the delift function takes in input a metavariable index, a local_context
* and a term t, and substitutes every subterm t' of t with its position
* (searched up-to unification) in