renaming

From: Quan Yuan (yq@cs.bu.edu)
Date: Wed Sep 29 2004 - 21:10:48 EDT 

Return-Path: <yq@cs.bu.edu>
Received: from cs.bu.edu (cs [128.197.12.2]) by cs3.bu.edu (8.12.11/8.12.11) with ESMTP id i8U08Ago023635 for <kfoury@cs3.bu.edu>; Wed, 29 Sep 2004 20:08:10 -0400
Received: from JELLYFISH (cumm111-0b01-dhcp167.bu.edu [128.197.11.167]) (authenticated bits=0) by cs.bu.edu (8.12.2/8.12.2) with ESMTP id i8U0889o026108 for <kfoury@cs.bu.edu>; Wed, 29 Sep 2004 20:08:10 -0400 (EDT)
Message-Id: <200409300008.i8U0889o026108@cs.bu.edu>
Date: Wed, 29 Sep 2004 20:10:48 -0500
From: "Quan Yuan" <yq@cs.bu.edu>
To: "Assaf J. Kfoury" <kfoury@cs.bu.edu>
Subject: renaming 
X-mailer: Foxmail 5.0 [en]
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Spam-HitLevel: xx
X-Spam-DCC: dcc.uncw.edu: cs3.bu.edu 1201; Body=1 Fuz1=1 Fuz2=1
X-Spam-Checker-Version: SpamAssassin 2.64 (2004-01-11) on cs3.bu.edu
X-Spam-Level: **
X-Spam-Status: No, hits=2.4 required=10.0 tests=AWL,MSGID_FROM_MTA_BACKUP  autolearn=no version=2.64
X-Spam-Pyzor: Reported 0 times.
Status: RO
X-Mozilla-Status: 8001
X-Mozilla-Status2: 00000000
X-UIDL: 411f69ec00000dc8

Professor,
For the implementation part of this assignment,
1. Do we just report error and exit when there are unbounded variables, like the implementation by Piece?
2. When we have a command like " \lambda y. (\lambda y. \lambda x. yx) y",
do we need to rename the y inside the paranthese? It seems we can use this term
in an application without variable capturing as long as there is no unbounded variables.

according to the substitution rules on top of [Piece, page 71],

 (\lambda y. (\lambda y. \lambda x. yx) y) (\lambda w.w)
=> (\lambda y. \lambda x. yx) (\lambda w.w)
=> \lambda x. (\lambda w. w) x

Thanks,

Quan

This archive was generated by hypermail 2b29 : Fri Nov 19 2004 - 17:00:43 EST