Talk:Free variables and bound variables

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The transition from the list of examples to the proposed precise definition, which I suspect may be too narrow, is abrupt. The article needs polishing, by someone familiar with logic and with the lambda calculus. Michael Hardy 22:51 Feb 23, 2003 (UTC)

The see also link for Closure appears to be the wrong kind of closure. It should probably be Closure (computer science). Glenn Willen (Talk) [[]] 16:18, 2 Sep 2004 (UTC)

I wonder if the explanation free to be varied as was recently inserted in the article is not misleading. My guess is that the etimologically bound variable precedes free variable. CSTAR 05:47, 13 Dec 2004 (UTC)

OK, I'm thinking about your first point. As to your second point, the words free and bound in common language go together so intimately that it's difficult to imagine one of the two having been introduced earlier than the other. Michael Hardy 23:47, 13 Dec 2004 (UTC)

What I had in mind was the following. (As I know you know) bound is used in a related sense: A variable binding is similar to an assignment (in both mathematical languages and in programming languages). Alternatively, we can say a variable is bound to a value. This sense of bound is certainly different than being within the scope of a binder although I am not exactly sure how to express the difference. CSTAR 00:19, 14 Dec 2004 (UTC)

PIVOT variable = BOUND variable DUMMY variable is (special case of) bound variable that can have only values 0 or 1.

The above is utter nonsense and is already covered in the article. Statisticians use the term "dummy variable" to mean something that can only be either 0 or 1. That is a completely different concept from that of dummy variable discussed in this article. And the article already says that. The "dummy variables" used by statisticians that only take the values 0 or 1 are NOT bound variables at all. Michael Hardy 22:31, 29 Apr 2005 (UTC)

I searched for "dummy variable" hopeing to get to the "indicator variable" page. There is a fundamental difference between the mathematical dummy variable and statistical dummy variable. Nevertheless, I think those who are searching for the statistical version (as I was) may be confused by what they read here. Unless they read through the article, they will not see the link to "indicator variable". In my opinion, rather than having a single line buried in the text stating that "unfortunately the term dummy variable is used by many statisticians to mean an indicator variable or some variant thereof", I have added a "for the statisitcal dummy variable..." link at the top. I think this should remove much of the confusion (at least the initial confusion I had). Mustard 20:41, 20 January 2006 (UTC)

We need to get rid of the redirect and have a proper article on statistical dummy variables. The link to indicator variables only makes things worse JQ 23:36, 23 April 2006 (UTC)

[edit] Recursive function link

Michael Hardy reverted the link I edited this morning. There are several places you could link the words recursive function to:

• computable function
• Recursion
• Recursion (computer science)

I'm not planning to edit the page again; decide for yourself which of the above links is the meaning you want. Note that recursive function is a disambiguation page, so you shouldn't link there.CMummert 02:13, 17 July 2006 (UTC)

Within this general area of mathematics, it usually means a computable function. Michael Hardy 17:53, 17 July 2006 (UTC)

That usage doesn't make sense in the sentence

Similarly, an identifier bound to a recursive function is also technically a free variable within its own body but is treated specially.

CMummert 17:55, 17 July 2006 (UTC)

I'm not going to vouch for all changes made throughout WP by CMummert from computable to recursive (since I haven't looked at them all) but I think in the instance being discussed here, his change is correct. Recursion in this instance means (a least) fixed point of some equation function. --CSTAR 19:04, 17 July 2006 (UTC)