# Math input methods

Jukka K. Korpela jkorpela at cs.tut.fi
Wed Jun 4 11:24:14 CDT 2014

```2014-06-04 17:42, Ian Clifton wrote:

> "Jukka K. Korpela" <jkorpela at cs.tut.fi> writes:
>
>> As an aside, the ISO 80000-2 standard on mathematical notations
>> describes boldface letters such as boldface R as symbols for commonly
>> known sets of numbers. The double-struck letters like ℝ as mentioned
>> as an alternative way, whereas in the previous standard, these
>> notations were presented the other way around. The change is logical
>> in the sense that bold face is a more original notation and
>> double-struck letters as characters imitate the imitation of boldface
>> letters when writing by hand (with a pen or piece of chalk).
>
> I’m not sure this is going to catch on with mathematicians, not least
> because bold letters are already heavily used, for vectors and matrices
> for instance.

Vectors and matrices are denoted by italic boldface letters, so there is
no confusion even in principle.

> My guess is mathematicians are going to stick to their
> double‐struck letters for these sets for as long as the year ∈ ℕ.

Mathematicians tend to be conservative in notations. They even use
italic for the constants i, e, and π, rather illogically and against
standards as well as common practices in natural sciences.

But still they have changed their notations somewhat. They do not use
the notations of Euclid and Archimedes any more. So maybe this will
change, too.

The interesting thing from the character code point of view is that
we’re now more or less expected to use rich text, at least bolding,
rather than just the special characters. In most writing situations, it
is easier to bold a letter than to enter the character ℝ—except when
typing plain text, of course. This is one reason why boldface might
become more common. On the other hand, when mathematicians write in
AMSTeX, both notations are equally easy to produce (once you know how to
do that).

In theory, we could use boldface in plain text, too, when writing
mathematical notations, e.g. U+1D411 MATHEMATICAL BOLD CAPITAL R. That’s
just not very practical, partly because they are outside the BMP and may
make programs choke, partly because font support is rather limited.

My math layout has combinations for typing the double-struck letters but
not for the math bold letters. It would of course be possible to create
a layout specifically for bold or italic or bold italic etc. math
symbols in Unicode, but their use seems to be too limited now.

Yucca

```