“Bun” Symbol for Direct Sum or Direct Product

[Chris Clemens]

Can you offer any advice on a symbol?

It looks like a circle with a cross inside. Not a multiplication cross, but a "plus-like" cross. It doesn't look like the examples shown in the Codebook or Instruction Manual for plus signs modified with circles.

http://en.wikipedia.org/wiki/Table_of_mathematical_symbols identifies this symbol as the "bun" symbol.

Do you suppose I should construct Plus modified by Circle, (or Circle modified by Plus)?

Have you seen or used this symbol before?

Any advice would be greatly appreciated.

Thank You.

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[Chris Clemens]

Hi. I don't believe this is actually a circle with a plus sign. I have attached a small .doc with the suggestion of using a circle with interior modification (horizontal bar and superposed vertical bar). Be sure whatever you use that you include in a tn or on the special symbols page the description of the print symbol. I based my suggestion on a symbol that is present in the Nemeth Code -- a square with interior diagonals-- which you can see on page 112 of the code book.

If anyone knows of a symbol that has already been created to represent this print sign, please advise.

[Chris Clemens]

Thanks, Dorothy.

You affirmed my fear. I was afraid I would have to use that unwieldy construction you came up with. I saw that square you mentioned, and hoped there was a more elegant solution.

While searching the interwebby for info on this symbol, I found a similar symbol with the cross appearing as a multiplication cross. So I may have a pair of unwieldy symbols.

Thanks again for your input.

[Chris Clemens]

There was a suggestion recently regarding a symbol that looks like a triangle pointing to the left -- that we follow rule XVI section 107. "Signs of shape which do not appear in the list of Basic Shapes must be represented by the use of one or more letters suggestive of the name of the shape being represented." Hopefully you haven't progressed too far with my earlier recommendation. It would be more efficient to use [braille]$bn for "bun", don't you think? And we would be adhering to the Nemeth Code. Or if your book is using different terminology, choose two letters to represent the name the authors have given the symbol.

[Chris Clemens]

At least one volume shipped with the "bun" symbol in it's unwieldy form.

Looking at sec. 107, the examples are a church and a moon. These things would be impossible to construct via modified shapes.

I'm satisfied with "Bun I" for this transcription, though I will definitely consider [braille]$BN in the future.

[Chris Clemens]

I would like to add my thoughts to this one. I agree that the symbol in question is not your "typical" plus sign in a circle. However, it IS called a "direct sum" in addition to the "bun" name. Unless the text actually says "bun", I think it would be clearer to the reader to acknowledge that it is a type of sum and do so using the shape indicator and ds rather than bn. Just another thought to add to the mix. We think we've seen it all until the next one comes along!

[Chris Clemens]

I agree that you should use letters that represent the name used in the text.

[Chris Clemens]

In the text, the author uses this symbol for External Direct Product.

He also acknowledges that different authors use other symbols, or other notation.

I found "bun" and "Direct Sum" on Wikipedia, and used that tern to facilitate conversing about the symbol.

Should I assume that one could use three letters for the symbol, i.e, [braille]$EDP because the text also refers to internal direct product.

[Chris Clemens]

Rule XVI sec. 107 says "one or more letters" so you could probably use 3. But wouldn't [braille]$ep and [braille]$ip do the job? I don't believe those shapes are already officially used for something else.

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