Definition talk:Ray (Order Theory)

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Sources: Mathworld and Munkres. Can't deal with figuring out how to type those up properly right now. --Dfeuer (talk) 13:08, 10 January 2013 (UTC)

Mathworld is renowned for being riddled with inaccuracies so please don't feel you have to cite that as a resource. --prime mover (talk) 13:55, 10 January 2013 (UTC)
I'll just have to add Munkres to the bibliography. --Dfeuer (talk) 14:01, 10 January 2013 (UTC)
The notation for upper and lower closures (i.e. the one using the arrows) should probably be used instead of the "ordered pair" version of the notation. (I didn't know about this notation till just now.) --prime mover (talk) 16:49, 10 January 2013 (UTC)
Maybe it's a regional variation? I've seen the admittedly problematic "ordered pair" version all the way from elementary or middle school up into college texts, and I've seen the obviously superior forwards-and-backwards square brace version in a grand total of about two printed texts (one was a very old intro topology book; one was a geometry text). --Dfeuer (talk) 17:27, 10 January 2013 (UTC)
"obviously superior forwards-and-backwards square brace"? Obviously superior? It's utter shit! It's the ugliest notation that's ever been invented! --prime mover (talk) 17:35, 10 January 2013 (UTC)