Nemeth Braille

For other uses, see Nemeth (disambiguation).

The Nemeth Braille Code for Mathematics is a Braille code for encoding mathematical and scientific notation linearly using standard six-dot Braille cells for tactile reading by the visually impaired. The code was developed by Abraham Nemeth. The Nemeth Code was first written up in 1952. It was revised in 1956, 1965, and 1972, and beginning in 1992 was integrated into Unified English Braille. It is an example of a compact human-readable markup language.

Nemeth Braille is just one code used to write mathematics in braille. There are many systems in use around the world.

Principles of the Nemeth Code

The Nemeth Code Book (1972) opens with the following words:

This Braille Code for Mathematics and Science Notation has been prepared to provide a system of symbols which will allow technical literature to be presented and read in braille. The Code is intended to convey as accurate an impression as is possible to the braille reader of the corresponding printed text, and this is one of its principal features. When the braille reader has a clear conception of the corresponding printed text, the area of communication between himself and his teacher, his colleagues, his associates, and the world at large is greatly broadened. A test of the accuracy with which the Code conveys information from the print to the braille text is to effect a transcription in the reverse direction. The amount of agreement between the original printed text and one transcribed from the braille is a measure of the Code's accuracy.

One consequence is that the braille transcriber does not need to know the underlying mathematics. The braille transcriber needs to identify the inkprint symbols, and to know how to render them in Nemeth Code braille. For example, if the same math symbol might have two different meanings, this would not matter. Both instances would be brailled the same. This is in contrast to the International Braille Music Code, where the braille depends on the meaning of the inkprint music. Thus a knowledge of music is required to produce braille music, but a knowledge of mathematics is not required to produce mathematical braille in the Nemeth code.

Table of Nemeth braille codes

General Signs

Symbol	*	,	…
Braille

Number Signs

Symbol	Number prefix	. / , (decimal)	, / . (separator)	0	1	2	3	4	5	6	7	8	9
Braille

Operators

Symbol	+	-	×		·	÷		=		. (decimal)	√	i√ (radical index)
Braille
Symbol	inner √ (1st)		inner √ (2nd)		end 1st √		end 2nd √			long division		/	!
Braille

Parentheses and Brackets

Symbol	(	)	[	]	{	}
Braille

Fractions

Symbol	simple		complex		hypercomplex		fraction in mixed number
	open	close	open	close	open	close	open	close
Braille

Symbol	/	―	complex /	complex ―	hypercomplex ―
Braille

Other modifiers

Symbol	∵	∴	∶	∷	′	″
Braille

Symbol	∞	∝	°	%	✓
Braille

Braille indicators

Symbol	Punctuation	Superscript	Subscript	Baseline	Omission	Cancel (close)	Cancel (open)	Run Over	Directly Over	Directly Under	Beginning	Termination
Braille

Comparison Signs

Symbol	>	<	≥	≤	≧	≦
Braille

Symbol	⋝	⋜	⪚	⪙
Braille

Symbol	><	<>	>=<	<=>
Braille

Symbol	≠	≱	≰	∼	≈	≅	±	∓
Braille

Geometry

Symbol	∥	$\perp$	∠	∟
Braille

Symbol	◡	◠		□	▭	▱
Braille

Symbol	◇		△	⊿	◯
Braille

Arrows

Symbol	⟶	⟵	⟷
Braille

Symbol	→	⇌	⇒
Braille

Trig functions

Function	Sine	Cosine	Tangent
Braille

Function	Secant	Cosecant	Cotangent	Logarithm
Braille

Set Theory

Symbol	∈	∋	∪	∩	∅	{}
Braille

Symbol	⊂	⊃	⊆	⊇
Braille

Misc. signs

Symbol	⊕	⊗	⊡
Braille

Symbol	Intersecting lines	@	Ditto	Tally mark	+-	-+
Braille

Symbol	|	≃	≡	―	| | (modulus)	. dot
Braille

Polygons

Symbol	Regular		Irregular
	Pentagon	Hexagon	Pentagon	Hexagon	Heptagon	Octagon	Nonagon
Braille

Triangles

Symbol	Acute	Isosceles	Obtuse	Scalene
Braille

Other signs

Symbol	Acute angle	Obtuse angle	Hexagon star	¶	§
Braille

Symbol	ref. indicator	<i>	<b>	letter sign	composite function	|det| matrix	∫	∂
Braille

Greek letters

Greek letters are based on the assignments of International Greek Braille.

Symbol	α	β	γ	δ	θ	μ	ν	π	ρ
Braille

Symbol	σ	ω	Σ	Δ	ϵ	λ	υ	φ
Braille

See also

• Gardner Salinas braille

External links

• Nemeth Code Made Easy by Christopher Weaver
• An Introduction to the Nemeth Braille Code for Mathematics
• PDF of the 1972 Nemeth Braille Code for Mathematics
• Braille files for the Nemeth Braille Code for Mathematics; and other resources about braille transcribing
• The History of Nemeth Code
• Braille Mathematical Notations: Different Braille Mathematical Codes from Around the World