On Fri, 31 Oct 2003 14:53:30 +0900 (JST), Nobuo Yamashita 
<nobsun / sampou.org> wrote:
>> Hugs session for:
>> /usr/share/hugs/lib/Prelude.hs
>> Type :? for help
>> Prelude> :l t.hs
>> ERROR "t.hs":4 - Syntax error in instance head (variable expected)
>
> ありゃ。なんでだ。 98 の範囲外かしらん。へんだなぁ。
> とりあえず、hugs を -98 オプション付きで起動してください。

Shiro さんも nobsun ももう確認していると思いますが、念のために報告。

ERROR "c:/develop/mail.lhs":11 - Inferred type is not general enough
*** Expression    : foo
*** Expected type : FooArg (Int,Int) => (Int,Int) -> a
*** Inferred type : FooArg (Int,Int) => (Int,Int) -> Int


GHCi では

Prelude> Compiling Main             ( c:/develop/mail.lhs, interpreted )

c:/develop/mail.lhs:10:
     Illegal instance declaration for `FooArg (Int, Int)'
	(The instance type must be of form (T a b c)
	 where T is not a synonym, and a,b,c are distinct type variables)
     In the instance declaration for `FooArg (Int, Int)'

c:/develop/mail.lhs:14:
     Illegal instance declaration for `FooArg (Int, Int, Int)'
	(The instance type must be of form (T a b c)
	 where T is not a synonym, and a,b,c are distinct type variables)
     In the instance declaration for `FooArg (Int, Int, Int)'
Failed, modules loaded: none.
Prelude> Leaving GHCi.


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