# HG changeset patch
# User wenzelm
# Date 1290811283 -3600
# Node ID aef83e8fa2a426ba96f54460b8ca7bec6c9d87d2
# Parent  29885c9be6ae134fbe94c6fcbe9c0b302211aa34# Parent  441260986b631b795b5eb81a0a6d905b0aea8076
merged

diff -r 29885c9be6ae -r aef83e8fa2a4 NEWS
--- a/NEWS	Fri Nov 26 23:12:01 2010 +0100
+++ b/NEWS	Fri Nov 26 23:41:23 2010 +0100
@@ -521,6 +521,9 @@
 
 *** ML ***
 
+* Former exception Library.UnequalLengths now coincides with
+ListPair.UnequalLengths.
+
 * Renamed raw "explode" function to "raw_explode" to emphasize its
 meaning.  Note that internally to Isabelle, Symbol.explode is used in
 almost all situations.
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Fun.thy
--- a/src/HOL/Fun.thy	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Fun.thy	Fri Nov 26 23:41:23 2010 +0100
@@ -155,11 +155,6 @@
   shows "inj f"
   using assms unfolding inj_on_def by auto
 
-text{*For Proofs in @{text "Tools/Datatype/datatype_rep_proofs"}*}
-lemma datatype_injI:
-    "(!! x. ALL y. f(x) = f(y) --> x=y) ==> inj(f)"
-by (simp add: inj_on_def)
-
 theorem range_ex1_eq: "inj f \<Longrightarrow> b : range f = (EX! x. b = f x)"
   by (unfold inj_on_def, blast)
 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Library/Sum_Of_Squares/sum_of_squares.ML
--- a/src/HOL/Library/Sum_Of_Squares/sum_of_squares.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Library/Sum_Of_Squares/sum_of_squares.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -103,11 +103,6 @@
 
 fun iszero (k,r) = r =/ rat_0;
 
-fun fold_rev2 f l1 l2 b =
-  case (l1,l2) of
-    ([],[]) => b
-  | (h1::t1,h2::t2) => f h1 h2 (fold_rev2 f t1 t2 b)
-  | _ => error "fold_rev2";
 
 (* Vectors. Conventionally indexed 1..n.                                     *)
 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Multivariate_Analysis/Convex_Euclidean_Space.thy
--- a/src/HOL/Multivariate_Analysis/Convex_Euclidean_Space.thy	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Multivariate_Analysis/Convex_Euclidean_Space.thy	Fri Nov 26 23:41:23 2010 +0100
@@ -19,7 +19,7 @@
 lemma injective_scaleR: 
 assumes "(c :: real) ~= 0"
 shows "inj (%(x :: 'n::euclidean_space). scaleR c x)"
-by (metis assms datatype_injI injI real_vector.scale_cancel_left)
+  by (metis assms injI real_vector.scale_cancel_left)
 
 lemma linear_add_cmul:
 fixes f :: "('m::euclidean_space) => ('n::euclidean_space)" 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Multivariate_Analysis/normarith.ML
--- a/src/HOL/Multivariate_Analysis/normarith.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Multivariate_Analysis/normarith.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -117,13 +117,6 @@
   [] => []
 | h::t => map (cons h) (combinations (k - 1) t) @ combinations k t
 
-
-fun forall2 p l1 l2 = case (l1,l2) of
-   ([],[]) => true
- | (h1::t1,h2::t2) => p h1 h2 andalso forall2 p t1 t2
- | _ => false;
-
-
 fun vertices vs eqs =
  let
   fun vertex cmb = case solve(vs,cmb) of
@@ -131,16 +124,16 @@
    | SOME soln => SOME (map (fn v => FuncUtil.Intfunc.tryapplyd soln v Rat.zero) vs)
   val rawvs = map_filter vertex (combinations (length vs) eqs)
   val unset = filter (forall (fn c => c >=/ Rat.zero)) rawvs
- in fold_rev (insert (uncurry (forall2 (curry op =/)))) unset []
+ in fold_rev (insert (eq_list op =/)) unset []
  end
 
-fun subsumes l m = forall2 (fn x => fn y => Rat.abs x <=/ Rat.abs y) l m
+val subsumes = eq_list (fn (x, y) => Rat.abs x <=/ Rat.abs y)
 
 fun subsume todo dun = case todo of
  [] => dun
 |v::ovs =>
-   let val dun' = if exists (fn w => subsumes w v) dun then dun
-                  else v::(filter (fn w => not(subsumes v w)) dun)
+   let val dun' = if exists (fn w => subsumes (w, v)) dun then dun
+                  else v:: filter (fn w => not (subsumes (v, w))) dun
    in subsume ovs dun'
    end;
 
@@ -246,10 +239,6 @@
   Const(@{const_name norm},_)$_ => arg_conv vector_canon_conv ct
  | _ => raise CTERM ("norm_canon_conv", [ct])
 
-fun fold_rev2 f [] [] z = z
- | fold_rev2 f (x::xs) (y::ys) z = f x y (fold_rev2 f xs ys z)
- | fold_rev2 f _ _ _ = raise UnequalLengths;
-
 fun int_flip v eq =
   if FuncUtil.Intfunc.defined eq v
   then FuncUtil.Intfunc.update (v, Rat.neg (FuncUtil.Intfunc.apply eq v)) eq else eq;
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Datatype/datatype.ML
--- a/src/HOL/Tools/Datatype/datatype.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Datatype/datatype.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -54,6 +54,8 @@
 val Suml_inject = @{thm Suml_inject};
 val Sumr_inject = @{thm Sumr_inject};
 
+val datatype_injI =
+  @{lemma "(!!x. ALL y. f x = f y --> x = y) ==> inj f" by (simp add: inj_on_def)};
 
 
 (** proof of characteristic theorems **)
@@ -438,8 +440,7 @@
                              Lim_inject :: inj_thms') @ fun_congs) 1),
                          atac 1]))])])])]);
 
-        val inj_thms'' = map (fn r => r RS @{thm datatype_injI})
-                             (split_conj_thm inj_thm);
+        val inj_thms'' = map (fn r => r RS datatype_injI) (split_conj_thm inj_thm);
 
         val elem_thm = 
             Skip_Proof.prove_global thy5 [] [] (HOLogic.mk_Trueprop (mk_conj ind_concl2))
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Datatype/datatype_aux.ML
--- a/src/HOL/Tools/Datatype/datatype_aux.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Datatype/datatype_aux.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -324,7 +324,7 @@
            \ nested recursion")
        | (SOME {index, descr, ...}) =>
            let val (_, vars, _) = (the o AList.lookup (op =) descr) index;
-               val subst = ((map dest_DtTFree vars) ~~ dts) handle Library.UnequalLengths =>
+               val subst = ((map dest_DtTFree vars) ~~ dts) handle ListPair.UnequalLengths =>
                  typ_error T ("Type constructor " ^ tname ^ " used with wrong\
                   \ number of arguments")
            in (i + index, map (fn (j, (tn, args, cs)) => (i + j,
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Datatype/datatype_prop.ML
--- a/src/HOL/Tools/Datatype/datatype_prop.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Datatype/datatype_prop.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -48,8 +48,8 @@
 
 fun make_tnames Ts =
   let
-    fun type_name (TFree (name, _)) = implode (tl (raw_explode name))  (* FIXME Symbol.explode (?) *)
-      | type_name (Type (name, _)) = 
+    fun type_name (TFree (name, _)) = unprefix "'" name
+      | type_name (Type (name, _)) =
           let val name' = Long_Name.base_name name
           in if Syntax.is_identifier name' then name' else "x" end;
   in indexify_names (map type_name Ts) end;
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Function/function_lib.ML
--- a/src/HOL/Tools/Function/function_lib.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Function/function_lib.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -44,11 +44,11 @@
 
 fun map4 _ [] [] [] [] = []
   | map4 f (x :: xs) (y :: ys) (z :: zs) (u :: us) = f x y z u :: map4 f xs ys zs us
-  | map4 _ _ _ _ _ = raise Library.UnequalLengths;
+  | map4 _ _ _ _ _ = raise ListPair.UnequalLengths;
 
 fun map7 _ [] [] [] [] [] [] [] = []
   | map7 f (x :: xs) (y :: ys) (z :: zs) (u :: us) (v :: vs) (w :: ws) (b :: bs) = f x y z u v w b :: map7 f xs ys zs us vs ws bs
-  | map7 _ _ _ _ _ _ _ _ = raise Library.UnequalLengths;
+  | map7 _ _ _ _ _ _ _ _ = raise ListPair.UnequalLengths;
 
 
 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Function/size.ML
--- a/src/HOL/Tools/Function/size.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Function/size.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -71,7 +71,7 @@
     val ((param_size_fs, param_size_fTs), f_names) = paramTs |>
       map (fn T as TFree (s, _) =>
         let
-          val name = "f" ^ implode (tl (raw_explode s));  (* FIXME Symbol.explode (?) *)
+          val name = "f" ^ unprefix "'" s;
           val U = T --> HOLogic.natT
         in
           (((s, Free (name, U)), U), name)
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Nitpick/nitpick_mono.ML
--- a/src/HOL/Tools/Nitpick/nitpick_mono.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Nitpick/nitpick_mono.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -393,7 +393,7 @@
   | do_mtype_comp cmp xs (M1 as MPair (M11, M12)) (M2 as MPair (M21, M22))
                   accum =
     (accum |> fold (uncurry (do_mtype_comp cmp xs)) [(M11, M21), (M12, M22)]
-     handle Library.UnequalLengths =>
+     handle ListPair.UnequalLengths =>
             raise MTYPE ("Nitpick_Mono.do_mtype_comp", [M1, M2], []))
   | do_mtype_comp _ _ (MType _) (MType _) accum =
     accum (* no need to compare them thanks to the cache *)
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Nitpick/nitpick_preproc.ML
--- a/src/HOL/Tools/Nitpick/nitpick_preproc.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Nitpick/nitpick_preproc.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -527,7 +527,7 @@
          | NONE =>
            Const (@{const_name Ex}, (T --> bool_T) --> bool_T)
            $ Abs (s, T, kill ss Ts ts))
-      | kill _ _ _ = raise UnequalLengths
+      | kill _ _ _ = raise ListPair.UnequalLengths
     fun gather ss Ts (Const (@{const_name Ex}, _) $ Abs (s1, T1, t1)) =
         gather (ss @ [s1]) (Ts @ [T1]) t1
       | gather [] [] (Abs (s, T, t1)) = Abs (s, T, gather [] [] t1)
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/Nitpick/nitpick_util.ML
--- a/src/HOL/Tools/Nitpick/nitpick_util.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/Nitpick/nitpick_util.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -204,7 +204,7 @@
 
 fun map3 _ [] [] [] = []
   | map3 f (x :: xs) (y :: ys) (z :: zs) = f x y z :: map3 f xs ys zs
-  | map3 _ _ _ _ = raise UnequalLengths
+  | map3 _ _ _ _ = raise ListPair.UnequalLengths
 
 fun double_lookup eq ps key =
   case AList.lookup (fn (SOME x, SOME y) => eq (x, y) | _ => false) ps
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/groebner.ML
--- a/src/HOL/Tools/groebner.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/groebner.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -233,14 +233,9 @@
 
 fun align  ((p,hp),(q,hq)) =
   if poly_lt p q then ((p,hp),(q,hq)) else ((q,hq),(p,hp));
-fun forall2 p l1 l2 =
-  case (l1,l2) of
-    ([],[]) => true
-  | (h1::t1,h2::t2) => p h1 h2 andalso forall2 p t1 t2
-  | _ => false;
 
 fun poly_eq p1 p2 =
-  forall2 (fn (c1,m1) => fn (c2,m2) => c1 =/ c2 andalso (m1: int list) = m2) p1 p2;
+  eq_list (fn ((c1, m1), (c2, m2)) => c1 =/ c2 andalso (m1: int list) = m2) (p1, p2);
 
 fun memx ((p1,h1),(p2,h2)) ppairs =
   not (exists (fn ((q1,_),(q2,_)) => poly_eq p1 q1 andalso poly_eq p2 q2) ppairs);
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/record.ML
--- a/src/HOL/Tools/record.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/record.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -917,7 +917,7 @@
                     val fields' = extern f :: map Long_Name.base_name fs;
                     val (args', more) = split_last args;
                   in (fields' ~~ args') @ strip_fields more end
-                  handle Library.UnequalLengths => [("", t)])
+                  handle ListPair.UnequalLengths => [("", t)])
               | NONE => [("", t)])
           | NONE => [("", t)])
        | _ => [("", t)]);
diff -r 29885c9be6ae -r aef83e8fa2a4 src/HOL/Tools/refute.ML
--- a/src/HOL/Tools/refute.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/HOL/Tools/refute.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -2953,9 +2953,7 @@
 fun stlc_printer ctxt model T intr assignment =
   let
     (* string -> string *)
-    fun strip_leading_quote s =
-      (implode o (fn [] => [] | x::xs => if x="'" then xs else x::xs)
-        o raw_explode) s  (* FIXME Symbol.explode (?) *)
+    val strip_leading_quote = perhaps (try (unprefix "'"))
     (* Term.typ -> string *)
     fun string_of_typ (Type (s, _)) = s
       | string_of_typ (TFree (x, _)) = strip_leading_quote x
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Pure/Proof/reconstruct.ML
--- a/src/Pure/Proof/reconstruct.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Pure/Proof/reconstruct.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -137,7 +137,7 @@
                 NONE => fold_map mk_tvar (map snd tvars @ map snd tfrees) env
               | SOME Ts => (Ts, env));
             val prop' = subst_atomic_types (map TVar tvars @ map TFree tfrees ~~ Ts)
-              (forall_intr_vfs prop) handle Library.UnequalLengths =>
+              (forall_intr_vfs prop) handle ListPair.UnequalLengths =>
                 error ("Wrong number of type arguments for " ^ quote (Proofterm.guess_name prf))
           in (prop', Proofterm.change_type (SOME Ts) prf, [], env', vTs) end;
 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Pure/consts.ML
--- a/src/Pure/consts.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Pure/consts.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -215,7 +215,7 @@
   let
     val declT = type_scheme consts c;
     val vars = map Term.dest_TVar (typargs consts (c, declT));
-    val inst = vars ~~ Ts handle UnequalLengths =>
+    val inst = vars ~~ Ts handle ListPair.UnequalLengths =>
       raise TYPE ("Consts.instance", Ts, [Const (c, dummyT)]);
   in declT |> Term_Subst.instantiateT inst end;
 
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Pure/drule.ML
--- a/src/Pure/drule.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Pure/drule.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -891,7 +891,7 @@
         handle TYPE (msg, _, _) => err msg;
 
     fun zip_vars xs ys =
-      zip_options xs ys handle Library.UnequalLengths =>
+      zip_options xs ys handle ListPair.UnequalLengths =>
         err "more instantiations than variables in thm";
 
     (*instantiate types first!*)
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Pure/library.ML
--- a/src/Pure/library.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Pure/library.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -58,7 +58,6 @@
   val setmp_thread_data: 'a Universal.tag -> 'a -> 'a -> ('b -> 'c) -> 'b -> 'c
 
   (*lists*)
-  exception UnequalLengths
   val single: 'a -> 'a list
   val the_single: 'a list -> 'a
   val singleton: ('a list -> 'b list) -> 'a -> 'b
@@ -97,6 +96,7 @@
   val eq_list: ('a * 'b -> bool) -> 'a list * 'b list -> bool
   val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
   val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
+  val fold_rev2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
   val forall2: ('a -> 'b -> bool) -> 'a list -> 'b list -> bool
   val zip_options: 'a list -> 'b option list -> ('a * 'b) list
   val ~~ : 'a list * 'b list -> ('a * 'b) list
@@ -321,8 +321,6 @@
 
 (** lists **)
 
-exception UnequalLengths;
-
 fun single x = [x];
 
 fun the_single [x] = x
@@ -495,7 +493,7 @@
       let val (ps, qs) = chop (length xs) ys
       in ps :: unflat xss qs end
   | unflat [] [] = []
-  | unflat _ _ = raise UnequalLengths;
+  | unflat _ _ = raise ListPair.UnequalLengths;
 
 fun burrow f xss = unflat xss (f (flat xss));
 
@@ -534,15 +532,17 @@
 
 (* lists of pairs *)
 
-exception UnequalLengths;
-
 fun map2 _ [] [] = []
   | map2 f (x :: xs) (y :: ys) = f x y :: map2 f xs ys
-  | map2 _ _ _ = raise UnequalLengths;
+  | map2 _ _ _ = raise ListPair.UnequalLengths;
 
 fun fold2 f [] [] z = z
   | fold2 f (x :: xs) (y :: ys) z = fold2 f xs ys (f x y z)
-  | fold2 f _ _ _ = raise UnequalLengths;
+  | fold2 f _ _ _ = raise ListPair.UnequalLengths;
+
+fun fold_rev2 f [] [] z = z
+  | fold_rev2 f (x :: xs) (y :: ys) z = f x y (fold_rev2 f xs ys z)
+  | fold_rev2 f _ _ _ = raise ListPair.UnequalLengths;
 
 fun forall2 P [] [] = true
   | forall2 P (x :: xs) (y :: ys) = P x y andalso forall2 P xs ys
@@ -558,13 +558,13 @@
 fun zip_options (x :: xs) (SOME y :: ys) = (x, y) :: zip_options xs ys
   | zip_options (_ :: xs) (NONE :: ys) = zip_options xs ys
   | zip_options _ [] = []
-  | zip_options [] _ = raise UnequalLengths;
+  | zip_options [] _ = raise ListPair.UnequalLengths;
 
 (*combine two lists forming a list of pairs:
   [x1, ..., xn] ~~ [y1, ..., yn]  ===>  [(x1, y1), ..., (xn, yn)]*)
 fun [] ~~ [] = []
   | (x :: xs) ~~ (y :: ys) = (x, y) :: (xs ~~ ys)
-  | _ ~~ _ = raise UnequalLengths;
+  | _ ~~ _ = raise ListPair.UnequalLengths;
 
 (*inverse of ~~; the old 'split':
   [(x1, y1), ..., (xn, yn)]  ===>  ([x1, ..., xn], [y1, ..., yn])*)
@@ -843,10 +843,11 @@
 
 fun map_transpose f xss =
   let
-    val n = case distinct (op =) (map length xss)
-     of [] => 0
+    val n =
+      (case distinct (op =) (map length xss) of
+        [] => 0
       | [n] => n
-      | _ => raise UnequalLengths;
+      | _ => raise ListPair.UnequalLengths);
   in map_range (fn m => f (map (fn xs => nth xs m) xss)) n end;
 
 
@@ -1066,3 +1067,5 @@
 
 structure Basic_Library: BASIC_LIBRARY = Library;
 open Basic_Library;
+
+datatype legacy = UnequalLengths;
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Pure/pattern.ML
--- a/src/Pure/pattern.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Pure/pattern.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -365,7 +365,7 @@
   and cases(binders,env as (iTs,itms),pat,obj) =
     let val (ph,pargs) = strip_comb pat
         fun rigrig1(iTs,oargs) = fold (mtch binders) (pargs~~oargs) (iTs,itms)
-				 handle UnequalLengths => raise MATCH
+				 handle ListPair.UnequalLengths => raise MATCH
         fun rigrig2((a:string,Ta),(b,Tb),oargs) =
               if a <> b then raise MATCH
               else rigrig1(typ_match thy (Ta,Tb) iTs, oargs)
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Tools/eqsubst.ML
--- a/src/Tools/eqsubst.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Tools/eqsubst.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -235,13 +235,13 @@
           val initenv =
             Envir.Envir {maxidx = ix2, tenv = Vartab.empty, tyenv = typinsttab};
           val useq = Unify.smash_unifiers thry [a] initenv
-              handle UnequalLengths => Seq.empty
+              handle ListPair.UnequalLengths => Seq.empty
                    | Term.TERM _ => Seq.empty;
           fun clean_unify' useq () =
               (case (Seq.pull useq) of
                  NONE => NONE
                | SOME (h,t) => SOME (mk_insts h, Seq.make (clean_unify' t)))
-              handle UnequalLengths => NONE
+              handle ListPair.UnequalLengths => NONE
                    | Term.TERM _ => NONE
         in
           (Seq.make (clean_unify' useq))
diff -r 29885c9be6ae -r aef83e8fa2a4 src/Tools/induct_tacs.ML
--- a/src/Tools/induct_tacs.ML	Fri Nov 26 23:12:01 2010 +0100
+++ b/src/Tools/induct_tacs.ML	Fri Nov 26 23:41:23 2010 +0100
@@ -96,7 +96,7 @@
     val _ = Method.trace ctxt [rule'];
 
     val concls = Logic.dest_conjunctions (Thm.concl_of rule);
-    val insts = maps prep_inst (concls ~~ varss) handle Library.UnequalLengths =>
+    val insts = maps prep_inst (concls ~~ varss) handle ListPair.UnequalLengths =>
       error "Induction rule has different numbers of variables";
   in res_inst_tac ctxt insts rule' i st end
   handle THM _ => Seq.empty;