let eval_ng_tac (text, prefix_len, tac) =
match tac with
| GrafiteAst.NApply (_loc, t) -> NTactics.apply_tac (text,prefix_len,t)
+ | GrafiteAst.NChange (_loc, w,ww) ->
+ NTactics.change_tac (text,prefix_len,w) (text,prefix_len,ww)
| GrafiteAst.NId _ -> fun x -> x
;;