Re: an odd ambiguity

Yes, the intent would be on the mrow. There are several notations that need
to have the intent on an mrow (maybe even a majority?). E.g, binomial and
integrals are two examples (although integral's intent is usually obvious,
discounting weird arXiv examples).

    Neil


On Wed, Aug 4, 2021 at 12:38 AM Paul Libbrecht <paul@hoplahup.net> wrote:

> One more interpretation is the use of the pipe-character as separator for
> coordinates in German’s schoolbooks.
>
> E.g.: http://oriesen.ch/doku/Raumgeometrie1S.pdf gives an example of that
> (on the second page): copied from the PDF: *Zeichne in der linken Figur
> die Punkte P ( 6 |3 |3 ) , Q ( 0 |4 |6 ) und R ( 1 |5 |3 ) ein.* (Which
> has quite a different spacing than in the PDF). In this usage and in this
> work, it seems that the spacing should be the same on both sides.
>
> As an “intent”, the whole notation made of “(“, the “|” and “)” should be
> considered. Is this planned in our intents syntax? Should the intent be on
> the mrow and can we avoid to pronounce the pipes?
>
> paul
>
> On 4 Aug 2021, at 6:27, Neil Soiffer wrote:
>
> We've mentioned how ambiguous "|" can be, but I don't remember seeing
> anyone mentioning this example:
> { x   ∣ x  ∣ 10}
> The set of all x such that x divides 10.
>
> In one expression are both the low priority separator "such that" and the
> medium priority relational operator "divides" (both are infix). There are
> two characters that *could *be used: vertical bar (U+007C) and divides
> (U+2223).  The Unicode Standard indicates that both should be U+2223 (I'm
> not sure that equivalence is correct)
>
> In TeX, there seems to be agreement that the first bar is be \mid.
> However, there seems to be disagreement for what to use for the second
> bar.
> <https://tex.stackexchange.com/questions/498/mid-vertical-bar-vert-lvert-rvert-divides>
> Some people suggest \mid, others "|", and still others \divides (which only
> exists in the MnSymbol package AFAIK). There are spacing differences and
> maybe height differences. Using different macros means there is a potential
> semantic distinction if the author actually uses them as opposed to using
> the ASCII "|". A reason TeX distinguishes them is that the spacing around
> the vertical bar differs a little. Someone will surely correct me on this
> if I'm wrong, but the spacing of these two uses is opposite their
> contextual meaning. TeX considers \mid to be a relational operator, but
> relational operators return boolean values -- \mid is really a
> separator/punctuation. On the other hand, \divides really is a relation (m
> divides n is either true or false), but it is spaced as a binary operator
> (at least in this context). Typographically, this is what is supposed to
> happen, but it seems counter-intuitive. Very strange.
>
> What does this mean for MathML? One thing is that in practice, software
> can't be sure the correct symbol is used in MathML (I leave it to someone
> else to report what TeX, ASCIIMath, and WYSIWYG editors use). The other
> issue is what the operator dictionary should say about the spacing and
> priority for these two symbols. Currently they both have the same spacing
> and priority, but that seems wrong.
>
> Thoughts?
>
>     Neil
>
>