Advertising billboards in Okazaki, Japan, featuring many different arrow symbols
An arrow is a graphical symbol, such as ← or →, or a pictogram, used to point or indicate direction. In its simplest form, an arrow is a triangle, chevron, or concave kite, usually
affixed to a line segment or rectangle,[1] and in more complex forms a representation of an actual arrow (e.g. ➵ U+27B5). The direction indicated by an arrow is the one along the length of the line or rectangle toward the single pointed end.
An older (medieval) convention is the manicule (pointing hand, 👈).
Pedro Reinel in c. 1504 first used the fleur-de-lis as indicating north in a compass rose;
the convention of marking the eastern direction with a cross is older (medieval).[2]
Use of the arrow symbol does not appear to pre-date the 18th century. An early arrow symbol is found in an illustration of Bernard Forest de Bélidor's treatise L'architecture hydraulique, printed in France in 1737. The arrow is here used to illustrate the direction of the flow of water and of the water wheel's rotation. At about the same time, arrow symbols were used to indicate the flow of rivers in maps.[3]
A trend toward abstraction, in which the arrow's fletching is removed, can be observed in the mid-to-late 19th century. The arrow can be seen in the work of Paul Klee. In a further abstraction of the symbol, John Richard Green's A Short History of the English People of 1874 contained maps by cartographer Emil Reich, which indicated army movements by curved lines, with solid triangular arrowheads placed intermittently along the lines.[4]
Use of arrow symbols in mathematical notation is still younger and developed in the first half of the 20th century.[5]David Hilbert in 1922 introduced the arrow symbol representing logical implication.
The double-headed arrow representing logical equivalence was introduced by Albrecht Becker in Die Aristotelische Theorie der Möglichkeitsschlüsse, Berlin, 1933.[4]
Usage
An exit sign with an arrow to indicate the exit is to the left
Arrows are universally recognised for indicating directions.[1] They are widely used on signage and for wayfinding,[1] and are often used in road surface markings.
Upward arrows are often used to indicate an increase in a numerical value, and downward arrows indicate a decrease.
In mathematical logic, a right-facing arrow indicates material conditional, and a left-right (bidirectional) arrow indicates if and only if, an upwards arrow indicates the NAND operator (negation of conjunction), an downwards arrow indicates the NOR operator (negation of disjunction).
Unicode
In Unicode, the block Arrows occupies the hexadecimal range U+2190–U+21FF, as described below.
Symbol
Name
Symbol
Name
Symbol
Name
Symbol
Name
Hex
Hex
Hex
Hex
Picture of this symbol
Picture of this symbol
Picture of this symbol
Picture of this symbol
←
Leftwards Arrow
↬
Rightwards Arrow With Loop
⇈
Upwards Paired Arrows
⇤
Leftwards Arrow To Bar
U+2190
U+21ac
U+21c8
U+21e4
Image:U+21AC.svg
Image:U+21C8.svg
↑
Upwards Arrow
↭
Left Right Wave Arrow
⇉
Rightwards Paired Arrows
⇥
Rightwards Arrow To Bar
U+2191
U+21ad
U+21c9
U+21e5
Image:U+21AD.svg
Image:U+21C9.svg
→
Rightwards Arrow
↮
Left Right Arrow With Stroke
⇊
Downwards Paired Arrows
⇦
Leftwards Thick Arrow
U+2192
U+21ae
U+21ca
U+21e6
Image:U+21AE.svg
Image:U+21CA.svg
↓
Downwards Arrow
↯
Downwards Zigzag Arrow
⇋
Leftwards Harpoon Over Rightwards Harpoon
⇧
Upwards Thick Arrow
U+2193
U+21af
U+21cb
U+21e7
Image:U+21AF.svg
Image:U+21CB.svg
↔
Left Right Arrow
↰
Upwards Arrow With Tip Leftwards
⇌
Rightwards Harpoon Over Leftwards Harpoon
⇨
Rightwards Thick Arrow
U+2194
U+21b0
U+21cc
U+21e8
Image:U+21B0.svg
Image:U+21CC.svg
↕
Up Down Arrow
↱
Upwards Arrow With Tip Rightwards
⇍
Leftwards Double Arrow With Stroke
⇩
Downwards Thick Arrow
U+2195
U+21b1
U+21 cd
U+21e9
Image:U+21B1.svg
Image:U+21CD.svg
↖
North West Arrow
↲
Downwards Arrow With Tip Leftwards
⇎
Left Right Double Arrow With Stroke
⇪
Upwards Thick Arrow From Bar
U+2196
U+21b2
U+21ce
U+21ea
Image:U+21B2.svg
Image:U+21CE.svg
↗
North East Arrow
↳
Downwards Arrow With Tip Rightwards
⇏
Rightwards Double Arrow With Stroke
⇫
Upwards Thick Arrow On Pedestal
U+2197
U+21b3
U+21cf
U+21eb
Image:U+21B3.svg
Image:U+21CF.svg
↘
South East Arrow
↴
Rightwards Arrow With Corner Downwards
⇐
Leftwards Double Arrow
⇬
Upwards Thick Arrow On Pedestal With Horizontal Bar
U+2198
U+21b4
U+21d0
U+21ec
Image:U+21B4.svg
Image:U+21D0.svg
↙
South West Arrow
↵
Downwards Arrow With Corner Leftwards
⇑
Upwards Double Arrow
⇭
Upwards Thick Arrow On Pedestal With Vertical Bar
U+2199
U+21b5
U+21d1
U+21ed
Image:U+21B5.svg
Image:U+21D1.svg
↚
Leftwards Arrow With Stroke
↶
Anticlockwise Top Semicircle Arrow
⇒
Rightwards Double Arrow
⇮
Upwards Thick Double Arrow
U+219a
U+21b6
U+21d2
U+21ee
Image:U+21B6.svg
Image:U+21D2.svg
↛
Rightwards Arrow With Stroke
↷
Clockwise Top Semicircle Arrow
⇓
Downwards Double Arrow
⇯
Upwards Thick Double Arrow On Pedestal
U+219b
U+21b7
U+21d3
U+21ef
Image:U+21B7.svg
Image:U+21D3.svg
↜
Leftwards Wave Arrow
↸
North West Arrow To Long Bar
⇔
Left Right Double Arrow
⇰
Rightwards Thick Arrow From Wall
U+219c
U+21b8
U+21d4
U+21f0
Image:U+21B8.svg
Image:U+21D4.svg
↝
Rightwards Wave Arrow
↹
Leftwards Arrow To Bar Over Rightwards Arrow To Bar
↑The American Revolution, 1775-1783: An Atlas of 18th Century Maps and Charts, Theatres of Operations, United States Naval History Division (1972), 14f.
↑E. H. Gombrich, "Pictorial Instructions" in: H. Barlow et al. (eds.), Images and understanding, Cambridge University Press (1990).
↑Green, J.J, Rossberg, M., and Ebert, P.A., : The Convenience of the Typesetter; Notation and Typography in Frege’s Grundgesetze der Arithmetik, Bulletin of Symbolic Logic 21 (2015): 13-30, fn. 17 [1] | DOI