+ | Dot _ -> "."
+ | Semicolon _ -> ";"
+ | Branch _ -> "["
+ | Shift _ -> "|"
+ | Pos (_, i) -> sprintf "%d:" i
+ | Merge _ -> "]"
+ | Focus (_, goals) ->
+ sprintf "focus %s" (String.concat " " (List.map string_of_int goals))
+ | Unfocus _ -> "unfocus"
+ | Skip _ -> "skip"
+
+and pp_tacticals ~sep tacs = String.concat sep (List.map pp_tactical tacs)