X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=ocaml%2Fsimple.ml;h=d600d30f6347a07697628181248d0c13856aff65;hb=73c253890a1f287278327aa49db613941ebf9527;hp=27d0119e58c505ba6918f43a02bf3bad879d8015;hpb=26ff6df470edda1ce022f1ba88e3769fe6323a4a;p=fireball-separation.git

diff --git a/ocaml/simple.ml b/ocaml/simple.ml
index 27d0119..d600d30 100644
--- a/ocaml/simple.ml
+++ b/ocaml/simple.ml
@@ -9,14 +9,42 @@ open Pure
 type var = int;;
 type t =
  | V of var
- | A of bool * t * t
+ | A of (bool ref) * t * t
  | L of (bool * t)
 ;;
 
-let rec measure_of_t = function
- | V _ -> 0
- | A(b,t1,t2) -> (if b then 1 else 0) + measure_of_t t1 + measure_of_t t2
- | L(b,t) -> if b then measure_of_t t else 0
+let measure_of_t =
+ let rec aux acc = function
+ | V _ -> acc, 0
+ | A(b,t1,t2) ->
+   let acc, m1 = aux acc t1 in
+   let acc, m2 = aux acc t2 in
+   if not (List.memq b acc) && !b then b::acc, 1 + m1 + m2 else acc, m1 + m2
+ | L(b,t) -> if b then aux acc t else acc, 0
+ in snd ++ (aux [])
+;;
+
+let index_of x =
+ let rec aux n =
+  function
+    [] -> None
+  | x'::_ when x == x' -> Some n
+  | _::xs -> aux (n+1) xs
+ in aux 1
+;;
+
+let sep_of_app =
+ let apps = ref [] in
+ function
+    r when not !r -> " "
+  | r ->
+    let i =
+     match index_of r !apps with
+        Some i -> i
+      | None ->
+         apps := !apps @ [r];
+         List.length !apps
+    in " " ^ string_of_int i ^ ":"
 ;;
 
 let string_of_t =
@@ -30,7 +58,7 @@ let string_of_t =
     | A _
     | L _ as t -> "(" ^ string_of_term_no_pars level t ^ ")"
   and string_of_term_no_pars_app level = function
-    | A(b,t1,t2) -> string_of_term_no_pars_app level t1 ^ (if b then "," else " ") ^ string_of_term_w_pars level t2
+    | A(b,t1,t2) -> string_of_term_no_pars_app level t1 ^ sep_of_app b ^ string_of_term_w_pars level t2
     | _ as t -> string_of_term_w_pars level t
   and string_of_term_no_pars level = function
     | L(_,t) -> "λ" ^ string_of_bvar level ^ ". " ^ string_of_term_no_pars (level+1) t
@@ -39,7 +67,7 @@ let string_of_t =
 ;;
 
 
-let delta = L(true,A(true,V 0, V 0));;
+let delta = L(true,A(ref true,V 0, V 0));;
 
 (* does NOT lift the argument *)
 let mk_lams = fold_nat (fun x _ -> L(false,x)) ;;
@@ -100,18 +128,26 @@ let rec no_leading_lambdas v n = function
  | V v' -> if v = v' then n else 0
 ;;
 
-(* b' defaults to false *)
+(* b' is true iff we are substituting the argument of a step
+   and the application of the redex was true. Therefore we need to
+   set the new app to true.  *)
 let rec subst b' level delift sub =
  function
  | V v -> if v = level + fst sub then lift level (snd sub) else V (if delift && v > level then v-1 else v)
  | L(b,t) -> L(b, subst b' (level + 1) delift sub t)
  | A(_,t1,(V v as t2)) when b' && v = level + fst sub ->
-    mk_app b' (subst b' level delift sub t1) (subst b' level delift sub t2)
+    mk_app (ref true) (subst b' level delift sub t1) (subst b' level delift sub t2)
  | A(b,t1,t2) ->
     mk_app b (subst b' level delift sub t1) (subst b' level delift sub t2)
+(* b is
+   - a fresh ref true if we want to create a real application from scratch
+   - a shared ref true if we substituting in the head of a real application *)
 and mk_app b' t1 t2 = if t1 = delta && t2 = delta then raise B
  else match t1 with
- | L(b,t1) -> subst (b' && not b) 0 true (0, t2) t1
+ | L(b,t1) ->
+    let last_lam = match t1 with L _ -> false | _ -> true in
+    if not b && last_lam then b' := false ;
+    subst (!b' && not b && not last_lam) 0 true (0, t2) t1
  | _ -> A (b', t1, t2)
 and lift n =
  let rec aux lev =
@@ -122,13 +158,13 @@ and lift n =
  in aux 0
 ;;
 let subst = subst false 0 false;;
-let mk_app = mk_app true;;
+let mk_app t1 = mk_app (ref true) t1;;
 
 let eta_eq =
  let rec aux t1 t2 = match t1, t2 with
   | L(_,t1), L(_,t2) -> aux t1 t2
-  | L(_,t1), t2 -> aux t1 (A(true,lift 1 t2,V 0))
-  | t1, L(_,t2) -> aux (A(true,lift 1 t1,V 0)) t2
+  | L(_,t1), t2 -> aux t1 (A(ref true,lift 1 t2,V 0))
+  | t1, L(_,t2) -> aux (A(ref true,lift 1 t1,V 0)) t2
   | V a, V b -> a = b
   | A(_,t1,t2), A(_,u1,u2) -> aux t1 u1 && aux t2 u2
   | _, _ -> false
@@ -244,36 +280,6 @@ let compute_max_lambdas_at hd_var j =
 
 let print_cmd s1 s2 = print_endline (">> " ^ s1 ^ " " ^ s2);;
 
-(* eat the arguments of the divergent and explode.
- It does NOT perform any check, may fail if done unsafely *)
-let eat p =
-print_cmd "EAT" "";
- let var, k = get_inert p.div in
- let phase = p.phase in
- let p =
-  match phase with
-  | `One ->
-      let n = 1 + max
-       (compute_max_lambdas_at var (k-1) p.div)
-       (compute_max_lambdas_at var (k-1) p.conv) in
-      (* apply fresh vars *)
-      let p, t = fold_nat (fun (p, t) _ ->
-        let p, v = freshvar p in
-        p, A(false, t, V (v + k))
-      ) (p, V 0) n in
-      let p = {p with phase=`Two} in
-      let t = A(false, t, delta) in
-      let t = fold_nat (fun t m -> A(false, t, V (k-m))) t (k-1) in
-      let subst = var, mk_lams t k in
-      let p = subst_in_problem subst p in
-      let _, args = get_inert p.div in
-      {p with div = inert_cut_at (args-k) p.div}
-  | `Two ->
-      let subst = var, mk_lams delta k in
-      subst_in_problem subst p in
- sanity p
-;;
-
 (* step on the head of div, on the k-th argument, with n fresh vars *)
 let step k n p =
  let var, _ = get_inert p.div in
@@ -281,20 +287,52 @@ print_cmd "STEP" ("on " ^ string_of_t (V var) ^ " (of:" ^ string_of_int n ^ ")")
  let p, t = (* apply fresh vars *)
   fold_nat (fun (p, t) _ ->
     let p, v = freshvar p in
-    p, A(false, t, V (v + k + 1))
+    p, A(ref false, t, V (v + k + 1))
   ) (p, V 0) n in
  let t = (* apply bound variables V_k..V_0 *)
-  fold_nat (fun t m -> A(false, t, V (k-m+1))) t (k+1) in
+  fold_nat (fun t m -> A(ref false, t, V (k-m+1))) t (k+1) in
  let t = mk_lams t (k+1) in (* make leading lambdas *)
  let subst = var, t in
  let p = subst_in_problem subst p in
  sanity p
 ;;
 
+let finish p =
+ let compute_max_arity =
+   let rec aux n = function
+   | A(_,t1,t2) -> max (aux (n+1) t1) (aux 0 t2)
+   | L(_,t) -> max n (aux 0 t)
+   | V _ -> n
+ in aux 0 in
+print_cmd "FINISH" "";
+ let div_hd, div_nargs = get_inert p.div in
+ let j = div_nargs - 1 in
+ let arity = compute_max_arity p.conv in
+ let n = 1 + arity + max
+  (compute_max_lambdas_at div_hd j p.div)
+  (compute_max_lambdas_at div_hd j p.conv) in
+ let p = step j n p in
+ let div_hd, div_nargs = get_inert p.div in
+ let rec aux m = function
+  A(_,t1,t2) -> if is_var t2 then
+   (let delta_var, _ = get_inert t2 in
+     if delta_var <> div_hd && get_subterm_with_head_and_args delta_var 1 p.conv = None
+      then m, delta_var
+      else aux (m-1) t1) else aux (m-1) t1
+  | _ -> assert false in
+ let m, delta_var = aux div_nargs p.div in
+ let p = subst_in_problem (delta_var, delta) p in
+ let p = subst_in_problem (div_hd, mk_lams delta (m-1)) p in
+ sanity p
+;;
+
 let rec auto p =
  let hd_var, n_args = get_inert p.div in
  match get_subterm_with_head_and_args hd_var n_args p.conv with
  | None ->
+   (try problem_fail (finish p) "Auto.2 did not complete the problem"
+   with Done sigma -> sigma)
+   (*
    (try
     let phase = p.phase in
      let p = eat p in
@@ -302,6 +340,7 @@ let rec auto p =
       then problem_fail p "Auto.2 did not complete the problem"
       else auto p
     with Done sigma -> sigma)
+    *)
  | Some t ->
   let j = find_eta_difference p t n_args in
   let k = 1 + max
@@ -311,7 +350,7 @@ let rec auto p =
   let p = step j k p in
   let m2 = measure_of_t p.div in
   (if m2 >= m1 then
-    (print_string "WARNING! Measure did not decrease (press <Enter>)";
+    (print_string ("WARNING! Measure did not decrease : " ^ string_of_int m2 ^ " >= " ^ string_of_int m1 ^ " (press <Enter>)");
     ignore(read_line())));
   auto p
 ;;
@@ -325,7 +364,7 @@ let problem_of (label, div, convs, ps, var_names) =
  | `N _ | `Match _ -> assert false in
  assert (List.length ps = 0);
  let convs = List.rev convs in
- let conv = List.fold_left (fun x y -> mk_app x (aux (y :> Num.nf))) (V (List.length var_names)) convs in
+ let conv = if List.length convs = 1 then aux (List.hd convs :> Num.nf) else List.fold_left (fun x y -> mk_app x (aux (y :> Num.nf))) (V (List.length var_names)) convs in
  let var_names = "@" :: var_names in
  let div = match div with
  | Some div -> aux (div :> Num.nf)