From: Jean-Christophe Filliatre <filliatr@lri.fr>
To: "Lukasz Stafiniak" <lukstafi@gmail.com>
Cc: "Jon Harrop" <jon@ffconsultancy.com>, caml-list@yquem.inria.fr
Subject: Re: [Caml-list] functions' recursive construction
Date: Wed, 23 May 2007 08:25:02 +0200 [thread overview]
Message-ID: <18003.56894.913446.961092@serveur9-10.lri.fr> (raw)
In-Reply-To: <4a708d20705221631x82b6e9ala0cd8b9d83baa959@mail.gmail.com>
Damien Lefortier wrote:
> I try to do a function f which takes one integer argument and returns
> a function g which returns its nth arguments.
>
> For example f 3 gives g with let g = fun x -> fun y -> fun z -> z ;;
Lukasz Stafiniak wrote:
> Would this function (or some approximation) be possible in Coq?
Yes, and here it is (0-based instead of 1-based as above):
======================================================================
Fixpoint t (n:nat) : Type := match n with
| O => forall (A:Set), A -> A
| S p => forall (A:Set), A -> t p
end.
Fixpoint f (n:nat) : t n :=
match n return t n with
| O => (fun (A:Set) (x:A) => x)
| S p => (fun (A:Set) (x:A) => f p)
end.
Eval compute in f 2.
= fun (A : Set) (_ : A) (A0 : Set) (_ : A0) (A1 : Set) (x1 : A1) => x1
: t 2
======================================================================
--
Jean-Christophe
next prev parent reply other threads:[~2007-05-23 6:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-22 23:17 Damien Lefortier
2007-05-22 23:21 ` [Caml-list] " Jon Harrop
2007-05-22 23:31 ` Lukasz Stafiniak
2007-05-22 23:32 ` Lukasz Stafiniak
2007-05-22 23:41 ` Jon Harrop
2007-05-23 6:25 ` Jean-Christophe Filliatre [this message]
2008-07-07 18:01 ` Fabrice Marchant
[not found] ` <a58674cc0807071304x1640d670sde3045a0920a5922@mail.gmail.com>
2008-07-07 18:28 ` Fabrice Marchant
2008-07-07 20:40 ` Jeremy Yallop
[not found] ` <C3DD7276-23D5-41BE-A272-7579586A5559@gmail.com>
2008-07-07 18:36 ` Fabrice Marchant
2008-07-07 20:25 ` Jeremy Yallop
2008-07-07 19:11 ` Fabrice Marchant
2008-07-07 22:48 ` asmadeus77
2008-07-08 9:24 ` Daniel Bünzli
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