# Re: Is a function a relation?

Date: Mon, 22 Jun 2009 22:35:58 -0700 (PDT)

Message-ID: <09f7bd9a-76f9-47c3-a4fd-8ef4556c2036_at_m19g2000yqk.googlegroups.com>

On Jun 23, 1:09 pm, Keith H Duggar <dug..._at_alum.mit.edu> wrote:

*>
*

> You considered the wrong relation values having the wrong

*> attribute names. Here are the correct values
**>
**> f(x) = x+1 -> { (domain,range) | range = domain + 1 }
**> g(y) = y+1 -> { (domain,range) | range = domain - 1 }
**>
**> corresponding to the f(x) and g(y) you gave.
*

So you're suggesting that a function is a relation where a special convention has been followed in the choice of attribute names? Yes that's one way of looking at it. That would in fact suggest the interesting idea that one can use the RA to define functions. E.g. start with some n-ary relation and use projection to get a binary relation, and rename as required according to this special naming convention. Received on Tue Jun 23 2009 - 07:35:58 CEST