Bug fixed in pretty-printing of original names under lambdas

[fireball-separation.git] / ocaml / num.ml

diff --git a/ocaml/num.ml b/ocaml/num.ml
index 69c87e046c9ab64093579be1868d8083419b30c6..e7b6290fc64afb7efb7212ac1bc0536067c3a3ab 100644 (file)
--- a/ocaml/num.ml
+++ b/ocaml/num.ml
@@ -118,7 +118,7 @@ let rec string_of_term =
  let boundvar x = "v" ^ string_of_int x in
  let varname lev l n =
   if n < lev then boundvar (lev-n-1)
-   else if n < List.length l then List.nth l (n-lev)
+   else if n - lev < List.length l then List.nth l (n-lev)
     else "`" ^ string_of_int (n-lev) in
  let rec string_of_term_w_pars lev l  = function
   | `Var(n,ar) -> varname lev l n ^ (if debug_display_arities then ":" ^ string_of_int ar else "")
@@ -127,7 +127,7 @@ let rec string_of_term =
   | `Lam _ as t -> "(" ^ string_of_term_no_pars_lam lev l t ^ ")"
   | `Match(t,(v,ar),bs_lift,bs,args) ->
       (* assert (bs_lift = lev); *)
-     "["^ varname lev l v ^ (if debug_display_arities then ":"^ string_of_int ar else "") ^",match " ^ string_of_term_no_pars lev l (t :> nf) ^
+     "(["^ varname 0 l v ^ (if debug_display_arities then ":"^ string_of_int ar else "") ^",match " ^ string_of_term_no_pars lev l (t :> nf) ^
      " with " ^ String.concat " | " (List.map (fun (n,t) -> string_of_int n ^ " => " ^ string_of_term l (t :> nf)) !bs) ^ "] " ^
      String.concat " " (List.map (string_of_term l) (args :> nf list)) ^ ")"
  and string_of_term_no_pars_app lev l  = function
@@ -230,12 +230,16 @@ and subst truelam delift_by_one what (with_what : nf) (where : nf) =
    | `N _ as x -> x
    | `Match(t,v,bs_lift,bs,args) ->
        let bs_lift = bs_lift + if delift_by_one then -1 else 0 in
+       (* Warning! It now applies again the substitution in branches of matches.
+          But careful, it does it many times, for every occurrence of
+          the match. This is okay because what does not occur in with_what. *)
        let l' = l - bs_lift  in
-       let with_what' = lift l' with_what in
+       let with_what' = lift l' (with_what :> nf) in
        (* The following line should be the identity when delift_by_one = true because we
           are assuming the ts to not contain lambda-bound variables. *)
        bs := List.map (fun (n,t) -> n,subst truelam false what with_what' t) !bs ;
-       mk_match (cast_to_i_num_var (aux_i_num_var l t)) v bs_lift bs (List.map (aux l) args)
+       let body = cast_to_i_num_var (aux_i_num_var l t) in
+       mk_match body v bs_lift bs (List.map (aux l) (args :> nf list))
  and aux l(*lift*) =
 (*function iii -> let res = match iii with*)
   function