Fixed eta_compare in the case Lam vs. Bot

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

diff --git a/ocaml/num.ml b/ocaml/num.ml
index c88a101312b3b4d1a0db272d11081bc05be1d228..aa9338c4c8d2d777fa45c5d0b74a85c376032dc7 100644 (file)
--- a/ocaml/num.ml
+++ b/ocaml/num.ml
@@ -132,7 +132,7 @@ 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 lev 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)) ^ ")"
   | `Bottom -> "BOT"
@@ -250,6 +250,9 @@ and subst truelam delift_by_one what (with_what : nf(*_nob*)) (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 :> nf) in
        (* The following line should be the identity when delift_by_one = true because we
@@ -292,8 +295,8 @@ let eta_compare x y =
   | `Pacman, `Pacman -> 0
   | `Lam _, `N _ -> -1
   | `N _, `Lam _ -> 1
-  | `Bottom, `Lam _
-  | `Lam _, `Bottom -> assert false (* TO BE UNDERSTOOD *)
+  | `Bottom, `Lam(_,t) -> -1
+  | `Lam(_,t), `Bottom ->  1
   | `Lam(_,t1), `Lam(_,t2) -> aux t1 t2
   | `Lam(_,t1), t2 -> - aux t1 (mk_app (lift 1 t2) (`Var(0,-666)))
   | t2, `Lam(_,t1) ->   aux t1 (mk_app (lift 1 t2) (`Var(0,-666)))