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1. • CommentRowNumber1.
   • CommentAuthorTobyBartels
   • CommentTimeJul 13th 2015
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   Author: TobyBartels
   Format: MarkdownItexJust some obvious stuff at [[maximal partial function]] to satisfy some links.

   Just some obvious stuff at maximal partial function to satisfy some links.

2. • CommentRowNumber2.
   • CommentAuthorMike Shulman
   • CommentTimeJul 13th 2015
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   Author: Mike Shulman
   Format: MarkdownItexIs $\nrightarrow$ a common notation for partial functions? I've seen $\rightharpoonup$ much more frequently.

   Is $\nrightarrow$ a common notation for partial functions? I’ve seen $\rightharpoonup$ much more frequently.

3. • CommentRowNumber3.
   • CommentAuthorTodd_Trimble
   • CommentTimeJul 13th 2015
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   Author: Todd_Trimble
   Format: MarkdownItexThe slash notation is something I'd associate more with general relations. Over at [[Engeler's lemma]] I adopted the $\rightharpoonup$ notation.

   The slash notation is something I’d associate more with general relations. Over at Engeler’s lemma I adopted the $\rightharpoonup$ notation.

4. • CommentRowNumber4.
   • CommentAuthorTobyBartels
   • CommentTimeJul 15th 2015
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   Author: TobyBartels
   Format: MarkdownItexI really wanted ‘⇸’, with a vertical bar, but LaTeX doesn\'t seem to have that, and the MathML doesn\'t come out right when I put it in with Unicode. Either way is fine with me.

   I really wanted ‘⇸’, with a vertical bar, but LaTeX doesn't seem to have that, and the MathML doesn't come out right when I put it in with Unicode. Either way is fine with me.

5. • CommentRowNumber5.
   • CommentAuthorMike Shulman
   • CommentTimeJul 15th 2015
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   Author: Mike Shulman
   Format: MarkdownItexWhat do you mean by "the MathML doesn't come out right?" I've used `⇸` for barred arrows elsewhere on the lab. (But I also don't think of it as meaning a partial function, rather a general relation or profunctor, just like $\nrightarrow$.)

   What do you mean by “the MathML doesn’t come out right?” I’ve used ⇸ for barred arrows elsewhere on the lab. (But I also don’t think of it as meaning a partial function, rather a general relation or profunctor, just like $\nrightarrow$.)

6. • CommentRowNumber6.
   • CommentAuthorTobyBartels
   • CommentTimeJul 19th 2015
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   Author: TobyBartels
   Format: MarkdownItexCompare the MathML in the HTML source of the lines below: $$ X \nrightarrow Y $$ $$ X ⇸ Y $$ The arrow in the top line is properly rendered as a relation, while the arrow in the bottom line is not. This potentially affects the spacing; in my browser, at least, there is space in the top line that the bottom line misses. It\'s not reasonable to expect iTeX to invent TeX-like names for every Unicode symbol, much less to guess at the proper catcode of a symbol given directly. What iTeX really needs is to respect `\mathrel`; then we could do this right. (Or I could put in direct MathML, but I really don\'t want to get into that!) So I generally try to avoid using symbols that iTeX doesn\'t know (unless I really like them).

   Compare the MathML in the HTML source of the lines below:

   $$X \nrightarrow Y$$ $$X ⇸ Y$$

   The arrow in the top line is properly rendered as a relation, while the arrow in the bottom line is not. This potentially affects the spacing; in my browser, at least, there is space in the top line that the bottom line misses.

   It's not reasonable to expect iTeX to invent TeX-like names for every Unicode symbol, much less to guess at the proper catcode of a symbol given directly. What iTeX really needs is to respect \mathrel; then we could do this right. (Or I could put in direct MathML, but I really don't want to get into that!) So I generally try to avoid using symbols that iTeX doesn't know (unless I really like them).

7. • CommentRowNumber7.
   • CommentAuthorMike Shulman
   • CommentTimeJul 20th 2015
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   Author: Mike Shulman
   Format: MarkdownItexI would rather use a correct symbol, even if the spacing comes out wrong, but I can see your point.

   I would rather use a correct symbol, even if the spacing comes out wrong, but I can see your point.