Needs random tests

Oh, I see what you mean now. No I would not pass that test. I'll modify the description to clarify that R will contain only unique pairs.

Yes that would be fine I think. But if I remember correctly in set theory the set [[1,1],[2,2],[2,2]] is equivalent to [[1,1],[2,2]]. R itself is also a set; a set of ordered pairs.

Yep, Stanford is working now. No idea what was wrong yesterday.

I have placed a blockquote for the readers convenience and changed the name philosophy to the title of the page where you land :). You are probably right that it is doubtful wheteher people will want to click/read the links.

I do intend to keep the excercise abstract as it is in fact a very abstract notion. To me that is part of the fun actually. Do you still have trouble opening the link (it is now beneath the blockquote)? For me its working both at home and at work.

I didn't mean you should rephrase, I just made the point you could rephrase without really losing meaning.

That link to Set Theory doesn't work BTW. May be an internal server or something; I don't think my connection is the problem.

The philosophy page has a nice explanation of reflexivity. Reflexivity is used a bit abstractly in this kata; would it be possible to make it more applied, using that example? Maybe include the test from the linked page; I don't see a lot of people clicking through to a page that's marked Philosophy .. :P (and then reading on to the end as well!)

Thanks. You have a good point. Instead of rephrasing I did some research to provide useful links to understand more about the topic.
Relations are an important concept in Logic/Math/Philosophy and a lot of more complex topics rely on ones knowledge of them. If the kata proves to be a success then I was planning on making a series out of it where people can learn a lot more about relations and at some point we can see some more interesting applications.

Well, garbage is an ugly word. But it relied on jargon too much, and not the kind of jargon I knew.

This is better, though it could be entirely rephrased without the words relation and reflexive and still doesn't explain what those words mean.

Why is reflexivity important? ATM, I'm just looking for arrays [a,a] in another array. I've solved the kata, but I have this nagging feeling there's a whole lot more to this story that's not being addressed.

Would this work for [1,2], [[1,1],[2,2],[2,2]] ?

I see nowhere in the description that isn't a valid R.

Thanks for your input Johan. From your reply I gather that my instructions were garbage :).

I have now rewritten the instructions to make it less abstract and added an image.

Let me know what you think.

I'm guessing the points in S are onedimensional, and a set is a collection of unique items.

Other than that, I have no idea what you're on about. What is meant by relation and reflexive ?

Ok, thanks - works;-)!

Thanks for your feedback.
I changed it.