Re: [EXTERNAL] Semantic Markup: mrow's are needed

[Responding to David' Fs email]

Yes, we want  to tell authors the right way to do something if they want it
interpreted correctly... but there may be many ways to do it. We also want
to develop a solution that doesn't require an onerous amount of work to
"fix up". Publishers can tell authors what they require, but ultimately,
they probably need to fix up in various ways the material they get and
those fixes should not be "start again from scratch". Hence, I claim this
is one metric by which we can judge proposals.

    Neil


On Fri, Jun 26, 2020 at 2:28 PM David Farmer <farmer@aimath.org> wrote:

>
> Isn't the point to tell developers and authors the preferred way
> to write their content so that it can be interpreted unambiguously?
>
> If someone puts out content that does not follow the recommendations,
> then we are in the exact same situation as currently:  heuristics
> and guesswork will attempt to figure out the meaning and then will
> use that to try to pronounce correctly.  That is all an author
> can expect, if they have not followed the guidelines.
>
> If an implicit mrow really is unambiguous in a particular situation,
> AND it is possible to mark up the semantics on the explicit
> content, then it seems okay to leave out the mrow.  But if the lack
> of an mrow leaves no good place to indicate the semantics (or, if
> that causes us to be in the undesirable situation of requiring a
> multiplicity of "correct" ways to mark it up), then the principles
> we have discussed point to requiring the mrow.  That is, requiring it
> if the author wants to follow the rules and ensure that the meaning
> is unambiguous.
>
> In Neil's example of "extra layer of mrows around the postfix
> factorials" it was not clear to me if those mrow's are where the
> semantic information should go.  This is the point/question I was
> trying to make above:  if the unambiguous implicit mrow's are where
> the semantic information should go, then we can't leave them out.
>
> My understanding is that we are trying to specify how authors
> can describe meaning, to not have too many different ways to do it,
> and to not say what happens if an author chooses not to make
> content that meets the accessibility guidelines.  Have I said that
> correctly?
>
>
> On Fri, 26 Jun 2020, Murray Sargent wrote:
>
> >
> > I guess I’m used to parsing UnicodeMath and LaTeX and am not confused by
> the examples below at all. It’s easy to add the
> > extra <mrow>’s if need be. Being mathematically inclined, I like
> succinct notations. Marking things up with lots of
> > syntactic sugar that can be easily inferred seems to be a step backward
> and introduces complexity that can be error
> > prone. If the usual operator precedence rules are to be overruled, then
> that’s when you need to add the extra <mrow>’s.
> > And I really like implicit <mrow>’s since they are unambiguous and
> facilitate reading MathML.
> >
> >
> >
> > In this vein, we really need to define a set of defaults that apply to
> K-12 math. Explicitly saying that an mfrac is an
> > ordinary fraction seems crazy and error prone. Furthermore we have to
> handle MathML that doesn’t have any such extra
> > markup and we can already do so reliably. Only non-default expressions
> need special markup.
> >
> >
> >
> > One other idea: I think the main goal is to be able to speak math
> expressions correctly. Being able to compute
> > non-default math expressions is a more advanced goal that’s worth
> pursuing but is clearly harder and shouldn’t delay our
> > coming up with a set of speech hints.
> >
> >
> >
> > Thanks,
> >
> > Murray
> >
> >
> >
> > Sent from Mail for Windows 10
> >
> >
> >
> > From: Neil Soiffer
> > Sent: Friday, June 26, 2020 7:40 AM
> > To: public-mathml4@w3.org
> > Subject: [EXTERNAL] Semantic Markup: mrow's are needed
> >
> >
> >
> > We have talked a little about needing proper mrow structure in order to
> mark up prefix/posfix/infix operators. For
> > example, the following can not be semantically marked up:
> >
> > <mrow>
> >
> >   <mi>m</mi>
> >
> >   <mo>!</mo>
> >
> >   <mi>n</mi>
> >
> >   <mo>!</mo>
> >
> > </mrow>
> >
> >
> >
> > It needs an extra layer of mrows around the postfix factorials in the
> mrow.
> >
> > <mrow>
> >
> >   <mrow>
> >
> >     <mi>m</mi>
> >
> >     <mo>!</mo>
> >
> >   </mrow>
> >
> >   <mrow>
> >
> >     <mi>n</mi>
> >
> >     <mo>!</mo>
> >
> >   </mrow>
> >
> > </mrow>
> >
> >
> >
> > Here's a case we haven't talked about: implicit mrows.
> >
> > <msqrt>
> >
> >   <mi>n</mi>
> >
> >   <mo>!</mo>
> >
> > </msqrt>
> >
> >
> >
> > There is no place to markup the factorial here either. Implicit mrows
> don't work for semantic markup.
> >
> >
> >
> > Given what MathML generators typically produce, I think this pretty much
> forces the need for a canonicalization tool for
> > anyone wanting to hand-remediate MathML. For a tool that wants to infer
> the semantics, it seems necessary also.
> >
> >
> >
> > More directly actionable though is what we should say in a MathML 4
> specification. Specifically,
> >
> >  *  Should we discourage or maybe even deprecate implicit mrows?
> >  *  Should we have stronger language encouraging "proper" mrow structure?
> >
> >
> >
> >
> >