Removed B and C from t, stepped from problem

diff --git a/ocaml/simple.ml b/ocaml/simple.ml
index e5e829a5accccbf0e37ce2fbefe62b4a6c9f0ed5..154992dd3f056dad04a1334eff68b75b7be211b7 100644 (file)
--- a/ocaml/simple.ml
+++ b/ocaml/simple.ml
@@ -11,8 +11,6 @@ type t =
  | V of var\r
  | A of t * t\r
  | L of t\r
- | B (* bottom *)\r
- | C of int\r
 ;;\r
 \r
 let delta = L(A(V 0, V 0));;\r
@@ -23,7 +21,6 @@ let eta_eq' =
   | L t1, t2 -> aux l1 (l2+1) t1 t2\r
   | t1, L t2 -> aux (l1+1) l2 t1 t2\r
   | V a, V b -> a + l1 = b + l2\r
-  | C a, C b -> a = b\r
   | A(t1,t2), A(u1,u2) -> aux l1 l2 t1 u1 && aux l1 l2 t2 u2\r
   | _, _ -> false\r
  in aux ;;\r
@@ -49,10 +46,8 @@ let string_of_t =
   let rec string_of_term_w_pars level = function\r
     | V v -> if v >= level then "`" ^ string_of_int (v-level) else\r
        string_of_bvar (level - v-1)\r
-    | C n -> "c" ^ string_of_int n\r
     | A _\r
     | L _ as t -> "(" ^ string_of_term_no_pars level t ^ ")"\r
-    | B -> "BOT"\r
   and string_of_term_no_pars_app level = function\r
     | 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
@@ -68,19 +63,18 @@ type problem = {
  ; div : t\r
  ; conv : t\r
  ; sigma : (var * t) list (* substitutions *)\r
- ; stepped : var list\r
  ; phase : [`One | `Two] (* :'( *)\r
 }\r
 \r
 let string_of_problem p =\r
  let lines = [\r
-  "[stepped] " ^ String.concat " " (List.map string_of_int p.stepped);\r
   "[DV] " ^ string_of_t p.div;\r
   "[CV] " ^ string_of_t p.conv;\r
  ] in\r
  String.concat "\n" lines\r
 ;;\r
 \r
+exception B;;\r
 exception Done of (var * t) list (* substitution *);;\r
 exception Fail of int * string;;\r
 \r
@@ -98,8 +92,7 @@ let rec is_inert =
  function\r
  | A(t,_) -> is_inert t\r
  | V _ -> true\r
- | C _\r
- | L _ | B -> false\r
+ | L _ -> false\r
 ;;\r
 \r
 let is_var = function V _ -> true | _ -> false;;\r
@@ -117,7 +110,6 @@ let rec no_leading_lambdas v n = function
  | L t -> 1 + no_leading_lambdas (v+1) n t\r
  | A _ as t -> let v', m = get_inert t in if v = v' then max 0 (n - m) else 0\r
  | V v' -> if v = v' then n else 0\r
- | B | C _ -> 0\r
 ;;\r
 \r
 let rec subst level delift sub =\r
@@ -128,11 +120,8 @@ let rec subst level delift sub =
   let t1 = subst level delift sub t1 in\r
   let t2 = subst level delift sub t2 in\r
   mk_app t1 t2\r
- | C _ as t -> t\r
- | B -> B\r
-and mk_app t1 t2 = if t2 = B || (t1 = delta && t2 = delta) then B\r
+and mk_app t1 t2 = if t1 = delta && t2 = delta then raise B\r
  else match t1 with\r
- | B -> B\r
  | L t1 -> subst 0 true (0, t2) t1\r
  | _ -> A (t1, t2)\r
 and lift n =\r
@@ -141,25 +130,21 @@ and lift n =
   | V m -> V (if m >= lev then m + n else m)\r
   | L t -> L (aux (lev+1) t)\r
   | A (t1, t2) -> A (aux lev t1, aux lev t2)\r
-  | C _ as t -> t\r
-  | B -> B\r
  in aux 0\r
 ;;\r
 let subst = subst 0 false;;\r
 \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
-  stepped=v::p.stepped;\r
-  sigma=sub::p.sigma}\r
+ let sigma = sub::p.sigma in\r
+ let div = try subst sub p.div with B -> raise (Done sigma) in\r
+ let conv = try subst sub p.conv with B -> raise (Fail(-1,"p.conv diverged")) in\r
+ {p with div; conv; sigma}\r
 ;;\r
 \r
 let get_subterm_with_head_and_args hd_var n_args =\r
  let rec aux lev = function\r
- | C _\r
- | V _ | B -> None\r
+ | V _ -> None\r
  | L t -> aux (lev+1) t\r
  | A(t1,t2) as t ->\r
    let hd_var', n_args' = get_inert t1 in\r
@@ -176,8 +161,6 @@ let rec purify = function
  | L t -> Pure.L (purify t)\r
  | A (t1,t2) -> Pure.A (purify t1, purify t2)\r
  | V n -> Pure.V n\r
- | C _ -> Pure.V max_int (* FIXME *)\r
- | B -> Pure.B\r
 ;;\r
 \r
 let check p sigma =\r
@@ -196,8 +179,6 @@ let check p sigma =
 \r
 let sanity p =\r
  print_endline (string_of_problem p); (* non cancellare *)\r
- if p.conv = B then problem_fail p "p.conv diverged";\r
- if p.div = B then raise (Done p.sigma);\r
  if p.phase = `Two && p.div = delta then raise (Done p.sigma);\r
  if not (is_inert p.div) then problem_fail p "p.div converged";\r
  p\r
@@ -244,7 +225,6 @@ let compute_max_lambdas_at hd_var j =
       else id) (max (aux hd t1) (aux hd t2))\r
  | L t -> aux (hd+1) t\r
  | V _ -> 0\r
- | _ -> assert false\r
  in aux hd_var\r
 ;;\r
 \r
@@ -332,7 +312,7 @@ let problem_of (label, div, convs, ps, var_names) =
  | Some div -> aux (div :> Num.nf)\r
  | None -> assert false in\r
  let varno = List.length var_names in\r
- let p = {orig_freshno=varno; freshno=1+varno; div; conv; sigma=[]; stepped=[]; phase=`One} in\r
+ let p = {orig_freshno=varno; freshno=1+varno; div; conv; sigma=[]; phase=`One} in\r
  (* initial sanity check *)\r
  sanity p\r
 ;;\r