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• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeJan 5th 2013
• (edited Jan 5th 2013)

created little entries

to go along with the previous entries

(whose $n$Forum-discussion is here)

All of this is part of the cohesion - table.

• CommentRowNumber2.
• CommentAuthorDavid_Corfield
• CommentTimeJan 7th 2013

So whenever we come across a $\mathbf{\Pi}$, we should replace it by ʃ, right? E.g., many in this section.

• CommentRowNumber3.
• CommentAuthorUrs
• CommentTimeJan 7th 2013

Maybe for the time being we can just state that ʃ is to be read synonymously with $\mathbf{\Pi}$, with the former potentially preferred in type theory, while the latter potentially preferred from the point of view of algebraic topology.

• CommentRowNumber4.
• CommentAuthorMike Shulman
• CommentTimeJan 7th 2013

Did we settle on ʃ? I thought there was some argument that the potential for confusion with an integral sign was undesirable. I kind of like $$$. • CommentRowNumber5. • CommentAuthorUrs • CommentTimeJan 7th 2013 You have to decide. To me the similarity of $\prod$ with $\mathbf{\Pi}$ seems to be of the same sort of that of $\int$ with ʃ. I am happy to live with both. The symbol “$” seems to raise the wrong associations in me, but I guess I can get used to it.

What is not practical for me (if that was suggested above, maybe) is to go and change all the numerous occurences of $\mathbf{\Pi}$ in all $n$Lab entries, all my published articles and all my preprints. Nor does it seem desireable to me.

I am happy with telling the reader at the beginning of each context which notation it should be.

• CommentRowNumber6.
• CommentAuthorTodd_Trimble
• CommentTimeJan 7th 2013

FWIW, I don’t like $that much, and like the integral-looking thing more (although I don’t know how to type it). I’d always feel$ was some LaTeX typo.

• CommentRowNumber7.
• CommentAuthorUrs
• CommentTimeJan 7th 2013

(although I don’t know how to type it)

see here

I’d always feel $was some LaTeX typo. Yes, that’s my first association, too. But I suppose I could get used to it. • CommentRowNumber8. • CommentAuthorMike Shulman • CommentTimeJan 8th 2013 I think it’s a shame if the use of$ in LaTeX means that we can’t ever also use it in mathematics. LaTeX uses % for comments, but we still feel free to use it for percentages. (-: And it seems unlikely to me that a LaTeX typo would ever actually produce a file which compiled and yet contained some \$ characters in the output. But I guess two data points suggests that more other mathematicians would also feel uncomfortable with it.

• CommentRowNumber9.
• CommentAuthorUrs
• CommentTimeJan 8th 2013
• (edited Jan 8th 2013)

But is there really an issue with “ʃ” ? To the extent that people think of ʃ$X$ as being “integral over $X$” where $X$ is a type, it actually makes sense: it can be thought of as the homotopy coend over $X$ thought of as a simplicial object. So the only sensible interpretatin of ʃ$X$ as an “integral over $X$” is actually the intended interpretation! So that’s good, not a problem.

I’d think.

• CommentRowNumber10.
• CommentAuthorMike Shulman
• CommentTimeJan 8th 2013

If you don’t think there’s a problem with ʃ, I’m okay with it. I guess in other contexts you would be integrating a function rather than a type. Okay, let’s go with ʃ.

Would you object if someone else happened to change $\mathbf{\Pi}$s to ʃs in an nLab page? I’m not planning to go through the whole nLab either, but if I happen to be editing some page anyway, I might want to make it consistent.

• CommentRowNumber11.
• CommentAuthorUrs
• CommentTimeJan 8th 2013

Okay, good, yes!

And I am fine with changing $\mathbf{\Pi}$s to ʃ, yes. I just feel overwhelmed with doing it globally and consistently.

(One fine day we might have $n$Lab-wide macros…)

• CommentRowNumber12.
• CommentAuthorMike Shulman
• CommentTimeJan 9th 2013

(That would be pretty cool.)