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Re: Math Arrows and Harpoons

At 09:45 +0100 1998/11/14, Taco Hoekwater wrote:
>>the case of 032 21B6 curvearrowleft 033 21B7 curvearrowright I feel sure
>> it is not essential that the arrowhead points down... It should
...
>Barbara, any comments from AFII? I'll mirror the other 5 arrows into
>new slots so there will be versions with and without angled heads.

If I should try to remember cases of usage, then it is in traffic warning
signs for a curvy road. -- Then some nations may have the arrow pointing
bent, as the AFII pointed out by Barbara, and other nations may have it as
in the LaTeX \leadsto symbol. For a traffic sign, the AFII variation may
look better, but I still think that for math \leadsto would be the best.

  As for the design of the arrowhead, I think that it should simply point
in the direction of the tangent of the shaft at the point where the
arrowhead starts.

  Take for example the "033 21B7 curvearrowright": If prolonged more and
more, the arrowhead would more and more point to the right. It its current
design, if one looks carefully at it, the arrowhead points a bit too much
down -- it should be a bit more to the right, to make it look better.

  One can also question whether the difference between the sharp/smooth
shaft corners of 030 and 131 are no more than a matter of style, and not
semantics.

  On shaft styles, I think there are variations like
    - . - . -      dotted dash
    -- . -- . --   dotted long dash
used by architects, cartographers, etc, even though I have not seen it in math.

>>   C204 has a strange name ...
>
>For clarity: this is char #204, (index
>F524). Try to use hashes for characters in fonts if you will to avoid
>confusion with the table indices.

It's a typo due to the following rule for math typesetting:

  A sentence should never start with a math symbol or expression, as it
will not look good in print.

  Computer scientists seem to not know about this rule, so I mentioned it
here. So I first started the sentence with "204" and thought "should I not
start the sentence with a letter?"... :-)

  Hans Aberg
                  * Email: Hans Aberg <mailto:haberg@member.ams.org>
                  * Home Page: <http://www.matematik.su.se/~haberg/>
                  * AMS member listing: <http://www.ams.org/cml/>