(** current goal, integer index *)
type goal = int
type status = proof * goal
+
(**
a tactic: make a transition from one status to another one or, usually,
raise a "Fail" (@see Fail) exception in case of failure
*)
(** an unfinished proof with the optional current goal *)
-type tactic = status:status -> proof * goal list
+type tactic = status -> proof * goal list
(** tactic failure *)
exception Fail of string