# Start a new discussion

## Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

## Site Tag Cloud

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

• CommentRowNumber1.
• CommentAuthorTodd_Trimble
• CommentTimeFeb 14th 2016

Over at rack, I noticed brief mention of the notion of shelf. As some of you will know, shelves also crop up in large cardinal axioms, so I gave shelf its own subsection and mentioned some of the lore (e.g., Laver tables). The topic might be worth a separate page.

• CommentRowNumber2.
• CommentAuthorMike Shulman
• CommentTimeFeb 14th 2016

Definitely worth its own page!

• CommentRowNumber3.
• CommentAuthorGuest
• CommentTimeOct 31st 2022

is it on purpose, that you swapped $\triangleright$ and $\triangleleft$ from the wikipedia definition? And if so, why?

• CommentRowNumber4.
• CommentAuthorzskoda
• CommentTimeNov 1st 2022

Dear Guest, please do some basic checking before accusing $n$labbers for laisy copying from wikipedia. The wikipedia article has been started in 2011, see https://en.wikipedia.org/w/index.php?title=Racks_and_quandles&action=history. The plethora of relations you refer to about the triangle left and right actions are in $n$Lab from 2010, see version 3 https://ncatlab.org/nlab/revision/rack/3. A left action in mathematics is more standardly denoted by triangle pointed to the left, which is LaTeX command triangleright, $\triangleright$. The conventions in the current wikipedia article are nonstandard.

• CommentRowNumber5.
• CommentAuthorGuest
• CommentTimeNov 2nd 2022
Dear zskoda, I am sorry for my wording, you are absolutely correct. Thank you for explaining! <3
• CommentRowNumber6.
• CommentAuthorzskoda
• CommentTimeNov 3rd 2022

You are welcome !