src/Pure/Isar/local_syntax.ML

     val local_syntax = thy_syntax
       |> Syntax.extend_trfuns
           (map Syntax.mk_trfun atrs, map Syntax.mk_trfun trs,
            map Syntax.mk_trfun trs', map Syntax.mk_trfun atrs')
       |> fold (uncurry (Syntax.extend_const_gram is_logtype))
-          (coalesce (op =) (rev (map snd mixfixes)));
+          (AList.coalesce (op =) (rev (map snd mixfixes)));
   in make_syntax (thy_syntax, local_syntax, mixfixes, idents) end;
 
 fun init thy = build_syntax thy ([], ([], []));
 
 fun rebuild thy (syntax as Syntax {mixfixes, idents, ...}) =