--- a/src/HOL/BNF/Tools/bnf_fp_rec_sugar.ML Sun Oct 20 19:20:08 2013 +0200
+++ b/src/HOL/BNF/Tools/bnf_fp_rec_sugar.ML Sun Oct 20 19:20:08 2013 +0200
@@ -176,22 +176,22 @@
subst bound_Ts g' $ subst bound_Ts y
else
let
- val maybe_mutual_y' = AList.lookup (op =) mutual_calls y;
- val maybe_nested_y_head' = AList.lookup (op =) nested_calls y_head;
val (g, g_args) = strip_comb g';
val ctr_pos = try (get_ctr_pos o the) (free_name g) |> the_default ~1;
val _ = ctr_pos < 0 orelse length g_args >= ctr_pos orelse
primrec_error_eqn "too few arguments in recursive call" t;
in
- if is_some maybe_nested_y_head' then
+ (case AList.lookup (op =) nested_calls y_head of
+ SOME y_head' =>
massage_nested_rec_call lthy has_call (rewrite_map_arg get_ctr_pos) bound_Ts y_head
- (the maybe_nested_y_head') t
- else if ctr_pos >= 0 then
- (case maybe_mutual_y' of
- NONE => t
- | SOME y' => list_comb (y', g_args))
- else
- t
+ y_head' t
+ | NONE =>
+ if ctr_pos >= 0 then
+ (case AList.lookup (op =) mutual_calls y of
+ NONE => t
+ | SOME y' => list_comb (y', g_args))
+ else
+ t)
end
end
| subst bound_Ts (Abs (v, T, b)) = Abs (v, T, subst (T :: bound_Ts) b)