Added garbage to L

Note: eta_eq ignores garbage at the moment

diff --git a/ocaml/simple.ml b/ocaml/simple.ml
index 897d6b68a4b736952774d4127e109020f2fb7618..a028b1f269015752f08833999edad20386d1cf52 100644 (file)
--- a/ocaml/simple.ml
+++ b/ocaml/simple.ml
@@ -10,11 +10,11 @@ type var = int;;
 type t =\r
  | V of var\r
  | A of t * t\r
- | L of t\r
+ | L of (t * t list (*garbage*))\r
  | C (* constant *)\r
 ;;\r
 \r
-let delta = L(A(V 0, V 0));;\r
+let delta = L(A(V 0, V 0),[]);;\r
 \r
 let rec is_stuck = function\r
  | C -> true\r
@@ -25,9 +25,9 @@ let rec is_stuck = function
 let eta_eq' =\r
  let rec aux l1 l2 t1 t2 = match t1, t2 with\r
   | _, _ when is_stuck t1 || is_stuck t2 -> true\r
-  | L t1, L t2 -> aux l1 l2 t1 t2\r
-  | L t1, t2 -> aux l1 (l2+1) t1 t2\r
-  | t1, L t2 -> aux (l1+1) l2 t1 t2\r
+  | L t1, L t2 -> aux l1 l2 (fst t1) (fst t2)\r
+  | L t1, t2 -> aux l1 (l2+1) (fst t1) t2\r
+  | t1, L t2 -> aux (l1+1) l2 t1 (fst t2)\r
   | V a, V b -> a + l1 = b + l2\r
   | A(t1,t2), A(u1,u2) -> aux l1 l2 t1 u1 && aux l1 l2 t2 u2\r
   | _, _ -> false\r
@@ -37,14 +37,14 @@ let eta_eq = eta_eq' 0 0;;
 (* is arg1 eta-subterm of arg2 ? *)\r
 let eta_subterm u =\r
  let rec aux lev t = if t = C then false else (eta_eq' lev 0 u t || match t with\r
- | L t -> aux (lev+1) t\r
+ | L(t,g) -> List.exists (aux (lev+1)) (t::g)\r
  | A(t1, t2) -> aux lev t1 || aux lev t2\r
  | _ -> false) in\r
  aux 0\r
 ;;\r
 \r
 (* does NOT lift the argument *)\r
-let mk_lams = fold_nat (fun x _ -> L x) ;;\r
+let mk_lams = fold_nat (fun x _ -> L(x,[])) ;;\r
 \r
 let string_of_t =\r
   let string_of_bvar =\r
@@ -61,7 +61,8 @@ let string_of_t =
     | A(t1,t2) -> string_of_term_no_pars_app level t1 ^ " " ^ string_of_term_w_pars level t2\r
     | _ as t -> string_of_term_w_pars level t\r
   and string_of_term_no_pars level = function\r
-    | L t -> "λ" ^ string_of_bvar level ^ ". " ^ string_of_term_no_pars (level+1) t\r
+    | L(t,g) -> "λ" ^ string_of_bvar level ^ ". " ^ string_of_term_no_pars (level+1) t\r
+       ^ (if g = [] then "" else String.concat ", " ("" :: List.map (string_of_term_w_pars level) g))\r
     | _ as t -> string_of_term_no_pars_app level t\r
   in string_of_term_no_pars 0\r
 ;;\r
@@ -111,7 +112,7 @@ let rec is_constant =
     C -> true\r
   | V _ -> false\r
   | A(t,_)\r
-  | L t -> is_constant t\r
+  | L(t,_) -> is_constant t\r
 ;;\r
 \r
 let rec get_inert = function\r
@@ -133,7 +134,7 @@ let args_of_inert =
 (* precomputes the number of leading lambdas in a term,\r
    after replacing _v_ w/ a term starting with n lambdas *)\r
 let rec no_leading_lambdas v n = function\r
- | L t -> 1 + no_leading_lambdas (v+1) n t\r
+ | L(t,_) -> 1 + no_leading_lambdas (v+1) n t\r
  | A _ as t -> let v', m = get_inert t in if V v = v' then max 0 (n - m) else 0\r
  | V v' -> if v = v' then n else 0\r
  | C -> 0\r
@@ -141,22 +142,29 @@ let rec no_leading_lambdas v n = function
 \r
 let rec subst level delift sub =\r
  function\r
- | V v -> if v = level + fst sub then lift level (snd sub) else V (if delift && v > level then v-1 else v)\r
- | L t -> let t = subst (level + 1) delift sub t in if t = B then B else L t\r
+ | V v -> (if v = level + fst sub then lift level (snd sub) else V (if delift && v > level then v-1 else v)), []\r
+ | L x -> let t, g = subst_in_lam (level+1) delift sub x in L(t, g), []\r
  | A (t1,t2) ->\r
-  let t1 = subst level delift sub t1 in\r
-  let t2 = subst level delift sub t2 in\r
-  mk_app t1 t2\r
- | C -> C\r
+  let t1, g1 = subst level delift sub t1 in\r
+  let t2, g2 = subst level delift sub t2 in\r
+  let t3, g3 = mk_app t1 t2 in\r
+  t3, g1 @ g2 @ g3\r
+ | C -> C, []\r
+and subst_in_lam level delift sub (t, g) =\r
+  let t', g' = subst level delift sub t in\r
+  let g'' = List.fold_left\r
+   (fun xs t ->\r
+     let x,y = subst level delift sub t in\r
+     (x :: y @ xs)) g' g in t', g''\r
 and mk_app t1 t2 = if t1 = delta && t2 = delta then raise B\r
  else match t1 with\r
- | L t1 -> subst 0 true (0, t2) t1\r
- | _ -> A (t1, t2)\r
+ | L x -> subst_in_lam 0 true (0, t2) x\r
+ | _ -> A (t1, t2), []\r
 and lift n =\r
  let rec aux lev =\r
   function\r
   | V m -> V (if m >= lev then m + n else m)\r
-  | L t -> L (aux (lev+1) t)\r
+  | L(t,g) -> L (aux (lev+1) t, List.map (aux (lev+1)) g)\r
   | A (t1, t2) -> A (aux lev t1, aux lev t2)\r
   | C -> C\r
  in aux 0\r
@@ -165,29 +173,36 @@ let subst = subst 0 false;;
 \r
 let subst_in_problem ((v, t) as sub) p =\r
 print_endline ("-- SUBST " ^ string_of_t (V v) ^ " |-> " ^ string_of_t t);\r
- {p with\r
-  div=subst sub p.div;\r
-  conv=subst sub p.conv;\r
-  sigma=sub::p.sigma}\r
+ let sigma = sub :: p.sigma in\r
+ let div, g = try subst sub p.div with B -> raise (Done sigma) in\r
+ assert (g = []);\r
+ let conv, f = try subst sub p.conv with B -> raise (Fail(-1, "p.conv diverged")) in\r
+ assert (g = []);\r
+ {p with div; conv; sigma}\r
 ;;\r
 \r
 let get_subterms_with_head hd_var =\r
- let rec aux lev inert_done = function\r
- | L t -> aux (lev+1) false t\r
- | C | V _ -> []\r
+ let rec aux lev inert_done g = function\r
+ | L(t,g') -> List.fold_left (aux (lev+1) false) g (t::g')\r
+ | C | V _ -> g\r
  | A(t1,t2) as t ->\r
    let hd_var', n_args' = get_inert t1 in\r
    if not inert_done && hd_var' = V (hd_var + lev)\r
-    then lift ~-lev t :: aux lev true t1 @ aux lev false t2\r
-    else aux lev true t1 @ aux lev false t2\r
- in aux 0 false\r
+    then lift ~-lev t :: aux lev false (aux lev true g t1) t2\r
+    else                 aux lev false (aux lev true g t1) t2\r
+ in aux 0 false []\r
 ;;\r
 \r
-let rec purify = function\r
- | L t -> Pure.L (purify t)\r
- | A (t1,t2) -> Pure.A (purify t1, purify t2)\r
- | V n -> Pure.V n\r
+let purify =\r
+ let rec aux = function\r
+ | L(t,g) ->\r
+    let t = aux (lift (List.length g) t) in\r
+    let t = List.fold_left (fun t g -> Pure.A(Pure.L t, aux g)) t g in\r
+    Pure.L t\r
+ | A (t1,t2) -> Pure.A (aux t1, aux t2)\r
+ | V n -> Pure.V (n)\r
  | C -> Pure.V (min_int/2)\r
+ in aux\r
 ;;\r
 \r
 let check p sigma =\r
@@ -252,7 +267,7 @@ let compute_max_lambdas_at hd_var j =
         then let hd', j' = get_inert t2 in j - j'\r
         else no_leading_lambdas hd_var j t2)\r
       else id) (max (aux hd t1) (aux hd t2))\r
- | L t -> aux (hd+1) t\r
+ | L(t,_) -> aux (hd+1) t\r
  | V _ | C -> 0\r
  in aux hd_var\r
 ;;\r
@@ -296,7 +311,7 @@ let finish p =
  let compute_max_arity =\r
    let rec aux n = function\r
    | A(t1,t2) -> max (aux (n+1) t1) (aux 0 t2)\r
-   | L t -> max n (aux 0 t)\r
+   | L(t,g) -> List.fold_right (max ++ (aux 0)) (t::g) 0\r
    | _ -> n\r
  in aux 0 in\r
 print_cmd "FINISH" "";\r