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1. • CommentRowNumber1.
   • CommentAuthorTobyBartels
   • CommentTimeOct 8th 2009
   • PermaLink
   Author: TobyBartels
   Format: Markdown[[pairing]] — pretty simple, but not to be confused with the product

   pairing — pretty simple, but not to be confused with the product

2. • CommentRowNumber2.
   • CommentAuthorTobyBartels
   • CommentTimeOct 9th 2009
   • PermaLink
   Author: TobyBartels
   Format: Markdown[[copairing]], with examples at [[interval object]]. [[domain]], as disambiguation

   copairing, with examples at interval object.

   domain, as disambiguation

3. • CommentRowNumber3.
   • CommentAuthorUrs
   • CommentTimeOct 9th 2009
   • PermaLink
   Author: Urs
   Format: Markdown<blockquote> [[copairing]] </blockquote> Thanks. Reminds me that I don't have the font installed that you use for the coproduct...

   This comment is invalid XHTML+MathML+SVG; displaying source. <div> <blockquote> <a href="https://ncatlab.org/nlab/show/copairing">copairing</a> </blockquote> <p>Thanks. Reminds me that I don't have the font installed that you use for the coproduct...</p> </div>
4. • CommentRowNumber4.
   • CommentAuthorUrs
   • CommentTimeOct 9th 2009
   • PermaLink
   Author: Urs
   Format: Markdown<blockquote> [[pairing]] — pretty simple, but not to be confused with the product </blockquote> Was that a hind in my direction, yb the way? I think I may have written "product" for "pairing" here and there. Not that I can't tell one from the other, but maybe I was not using good terminology.

   This comment is invalid XHTML+MathML+SVG; displaying source. <div> <blockquote> <a href="https://ncatlab.org/nlab/show/pairing">pairing</a> — pretty simple, but not to be confused with the product </blockquote> <p>Was that a hind in my direction, yb the way? I think I may have written "product" for "pairing" here and there. Not that I can't tell one from the other, but maybe I was not using good terminology.</p> </div>
5. • CommentRowNumber5.
   • CommentAuthorTobyBartels
   • CommentTimeOct 9th 2009
   • PermaLink
   Author: TobyBartels
   Format: MarkdownIt wasn't meant to be a *hint*, but I wrote it to link it from [[interval object]], where you had not only written ‘product’ for ‘pairing’ but had also denoted copairing as if it were a coproduct. But I fixed all that.

   It wasn't meant to be a hint, but I wrote it to link it from interval object, where you had not only written ‘product’ for ‘pairing’ but had also denoted copairing as if it were a coproduct.

   But I fixed all that.

6. • CommentRowNumber6.
   • CommentAuthorUrs
   • CommentTimeOct 9th 2009
   • PermaLink
   Author: Urs
   Format: MarkdownDo you mean writing <latex> f \coprod g : x \coprod y \to z</latex> ? Isn't that standard notation?

   Do you mean writing ? Isn't that standard notation?

7. • CommentRowNumber7.
   • CommentAuthorTobyBartels
   • CommentTimeOct 10th 2009
   • PermaLink
   Author: TobyBartels
   Format: MarkdownIt's not the standard that I'm aware of. If <latex>f\colon x \to z</latex> and <latex>g\colon y \to z'</latex>, then <latex>f \amalg g\colon x \amalg y \to z \amalg z'</latex>. But if <latex>z'</latex> is the same as <latex>z</latex>, then we also have <latex>[f,g]\colon x \amalg y \to z</latex>. The relation between these (or rather, their duals) is discussed in detail at [[pairing]]. There are lots of notations for the [[copairing]] <latex>[f,g]</latex> and I suppose that somebody might write it as <latex>f \amalg g</latex>, but that conflicts with the idea that <latex>\amalg\colon C^2 \to C</latex> is a functor, which is reflected in my <latex>f \amalg g</latex>. Of course, if you keep track of the targets, then there's no actual conflict, but it doesn't seem right to me.

   It's not the standard that I'm aware of.

   If and , then .

   But if is the same as , then we also have .

   The relation between these (or rather, their duals) is discussed in detail at pairing.

   There are lots of notations for the copairing and I suppose that somebody might write it as , but that conflicts with the idea that is a functor, which is reflected in my . Of course, if you keep track of the targets, then there's no actual conflict, but it doesn't seem right to me.

8. • CommentRowNumber8.
   • CommentAuthorTodd_Trimble
   • CommentTimeOct 10th 2009
   • (edited Oct 10th 2009)
   • PermaLink
   Author: Todd_Trimble
   Format: MarkdownI'm not sure that there is a strong consensus on notation here; my own has been to use <latex>\langle f, g\rangle</latex> for pairing and <latex>(f, g)</latex> for copairing. Like Toby, I would reserve <latex>\bigsqcup</latex> (or more often just <latex>+</latex>) for the bifunctor. Wait: how do I activate LaTeX formulas here again? [Note: I've edited after figuring this out]

   I'm not sure that there is a strong consensus on notation here; my own has been to use for pairing and for copairing. Like Toby, I would reserve (or more often just ) for the bifunctor.

   Wait: how do I activate LaTeX formulas here again? [Note: I've edited after figuring this out]

9. • CommentRowNumber9.
   • CommentAuthorTodd_Trimble
   • CommentTimeOct 10th 2009
   • PermaLink
   Author: Todd_Trimble
   Format: MarkdownOkay, testing... <latex>x^2 + y^2</latex>

   Okay, testing...

   
10. • CommentRowNumber10.
    • CommentAuthorUrs
    • CommentTimeOct 10th 2009
    • PermaLink
    Author: Urs
    Format: MarkdownOkay.

    Okay.

11. • CommentRowNumber11.
    • CommentAuthorMike Shulman
    • CommentTimeOct 10th 2009
    • PermaLink
    Author: Mike Shulman
    Format: MarkdownI agree that there's no consensus on notation, but I also agree that <latex>\sqcup</latex> or <latex>+</latex> should be reserved for the bifunctor.

    I agree that there's no consensus on notation, but I also agree that or should be reserved for the bifunctor.