User talk:TobyK

Welcome!

Hello, TobyK, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful:

I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you need help, check out Wikipedia:Questions, ask me on my talk page, or place {{helpme}} on your talk page and someone will show up shortly to answer your questions. Again, welcome! HighInBC ^{(Need help? Ask me)} 18:15, 3 November 2006 (UTC)[reply]

An article in a book of yours has been deleted

Hi TobyK:

This is to let you know that the article Cross generation ship which is included in your book [[space colonization]] has been deleted. Thanks for your efforts in providing books.

Fartherred (talk) 19:29, 2 March 2012 (UTC)[reply]

Lambda Calculus alpha conversion syntax

Hi,

You added the following text to Lambda Calculus:

${\textstyle (\lambda x.M[x])\rightarrow (\lambda y.M[y])}$ : α-conversion, renaming the bound variables in the expression.

I don't recognize the way you have used square brackets here. ${\textstyle (\lambda x.M)\rightarrow (\lambda y.M[x:=y])}$ would be more conventional. I know this conventional syntax is less symmetrical, but I can't imagine how ${\textstyle (\lambda x.M[x])\rightarrow (\lambda y.M[y])}$ would mean anything, rigorously speaking. If there's some syntactical convention that I don't know about, maybe you can explain it. I suspect this is just a mistake. Theoh (talk) 15:40, 25 October 2023 (UTC)[reply]

You are right it is not the conventional syntax in lambda calculus theory, but I think it better expresses how the variable name is a parameter of the expression which is changed. I think the conventional form looks like assignment rather than renaming and is unintuitive to non-experts. TobyK (talk) 22:49, 6 November 2023 (UTC)[reply]