1.1 --- a/src/HOL/Tools/function_package/fundef_common.ML	Mon Apr 20 12:27:23 2009 +0200
     1.2 +++ b/src/HOL/Tools/function_package/fundef_common.ML	Tue Apr 21 09:53:24 2009 +0200
     1.3 @@ -215,21 +215,6 @@
     1.4        (fname, qs, gs, args, rhs)
     1.5      end
     1.6  
     1.7 -exception ArgumentCount of string
     1.8 -
     1.9 -fun mk_arities fqgars =
    1.10 -    let fun f (fname, _, _, args, _) arities =
    1.11 -            let val k = length args
    1.12 -            in
    1.13 -              case Symtab.lookup arities fname of
    1.14 -                NONE => Symtab.update (fname, k) arities
    1.15 -              | SOME i => (if i = k then arities else raise ArgumentCount fname)
    1.16 -            end
    1.17 -    in
    1.18 -      fold f fqgars Symtab.empty
    1.19 -    end
    1.20 -
    1.21 -
    1.22  (* Check for all sorts of errors in the input *)
    1.23  fun check_defs ctxt fixes eqs =
    1.24      let
    1.25 @@ -269,13 +254,14 @@
    1.26                       " occur" ^ plural "s" "" funvars ^ " in function position.",  
    1.27                       "Misspelled constructor???"]); true)
    1.28            in
    1.29 -            fqgar
    1.30 +            (fname, length args)
    1.31            end
    1.32 -          
    1.33 -      val _ = mk_arities (map check eqs)
    1.34 -          handle ArgumentCount fname => 
    1.35 -                 error ("Function " ^ quote fname ^ 
    1.36 -                        " has different numbers of arguments in different equations")
    1.37 +
    1.38 +      val _ = AList.group (op =) (map check eqs)
    1.39 +        |> map (fn (fname, ars) =>
    1.40 +             length (distinct (op =) ars) = 1
    1.41 +             orelse error ("Function " ^ quote fname ^
    1.42 +                           " has different numbers of arguments in different equations"))
    1.43  
    1.44        fun check_sorts ((fname, fT), _) =
    1.45            Sorts.of_sort (Sign.classes_of (ProofContext.theory_of ctxt)) (fT, HOLogic.typeS)