# Re: Math Arrows and Harpoons

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: Re: Math Arrows and Harpoons
• From: Hans Aberg <haberg@matematik.su.se>
• Date: Fri, 13 Nov 1998 23:49:28 +0100
• Content-Length: 3820

```I made a classification of those arrows: It means that that I think that
most (if not all) of the arrows may be generated by the rules below.
Conversely, one can see from the classification what principle I think lies
behind the construction of the different arrows.

Clearly just a draft, but perhaps of some help.

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none
simple                      002
double                      015
triple                      ->>>
harpoon-[up,down]           [038,039]
triangle (or unfilled)      180

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Shaft shape

simple                              002
double                              053
triple                              065
bend-[up,down]                      033
bend-twice-[up,down]                [120,?]
bend-3-[up,down]                    [?,122]
circle-[clockwise,anti-clockwise]   [188,187]
wiggly                              126
zigzag                              211

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Shaft Bend: An arrow can bend sharply at need.

corner-[up,down]                    [028,029]
smooth corner-[up,down]             [130,131]

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Shaft continuity

continuous      002
broken          193

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Shaft length: The shaft may come in different lengths, but
as far as I know, it does not affect the semantic meaning of the
arrow.

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Shaft style

----        continuous      002
-- -- --    long dashed     073
- - -       dashed          075
....        dotted          077

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Shaft ornament

slash (negation)        011
vertical                175
circle                  179
cross                   172

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Tail

none                    002
simple                  018
double                  117
triple                  >>>--
vertical                019
hook-[up,down]          [080,082]
double-hook (fish-tail) 088
loop-[up,down]          [026,?]
fork                    199
circle                  012

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Compound Arrows:

o   Two can be laid side by side (050).
o   The arrows can then have different size (169).
o   The shaft can have a label (on either side) (145, 138,139).
o   The head can point directly to another symbol (136).
o   The tail can point directly to another symbol (203).
o   An arrow can be drawn on top of another arrow (194).
o   Perhaps replace [up,down] by [clockwise,anti-clockwise]
(or [positive,negative] direction of turn).

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Spurios Symbols

200 Perhaps a shaft with an ornament.
204 Not an arrow or an arrow-component as it stands.

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Hans Aberg
* Email: Hans Aberg <mailto:haberg@member.ams.org>