This page shows three set of examples illustrating some of the differences between the representation of subscripts and superscripts in Nemeth mathematics and in the UEB. Each set of examples is followed by a brief explanation. It is assumed that the reader is familiar with Nemeth.
Some UEB mathematical expressions have different forms depending on whether the expressions are displayed on a separate line or embedded in text. A subscript or superscript indicator in an expression embedded in a Grade 2 passage must be preceded by the Grade 1 indicator, (dots 56), unless Grade 1 mode is already in force.
| ex+y | x2+y2 | |
| Nemeth | e^x+y | x^2"+y^2 |
| UEB (displayed) | e9<x"6y> | x9#b"6y9#b |
| UEB (embedded)* | e;9<x"6y> | x;9#b"6y9#b |
Nemeth The start of a first-order subscript or superscript is the first cell after the level indicator and the end of a first-order subscript or superscript is the last cell just before either an explicit baseline indicator (dot 5); a naturally occurring mathematical comma, space, or line break; or the end of the overall expression. The Nemeth code does not require (or permit) the transcriber to insert extra grouping symbols around around a subscripted or superscripted expression.
The Nemeth superscript indicator is (dots 45), the subscript indicator is (dots 56), and the baseline indicator is (dot 5).
UEB The UEB requires the transcriber to insert a pair of special braille grouping indicators around a subscripted or superscripted expression unless that expression already qualifies as a single item. The start of the subscript or superscript is indicated by the opening grouping indicator or the start of the single item and the end of the subscript or superscript is indicated by the closing grouping indicator or the end of the single item.
Single items are defined as numbers, single symbols, fractions, radicals, shapes, arrows, and items enclosed in any pair of matching grouping symbols in print.
The UEB superscript indicator is (dots 35), the subscript indicator is (dots 26), the opening grouping indicator is (dots 126), and the closing grouping indicator is (dots 345).
| H2O | c0x | |
| Nemeth | ,h2,o | c0x |
| UEB (displayed) | ,h5#b,o | c5#jx |
| UEB (embedded)* | ,h;5#b,o | c;5#jx |
Nemeth The Nemeth code does not use a subscript indicator when a number is a first-order subscript to a letter or similar symbol that is on the baseline. The purpose of the the Numeric Subscript rule is to simplify the transcription of chemical formulas and indexed coefficients.
UEB The UEB does not have a special convention for numeric subscripts. Note also that, unless the Grade 1 mode is in force, chemical formulas, such as H2O, will be transcribed one way when they are embedded in a sentence like this one and a different way when they are part of a displayed chemical equation.
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| Nemeth | e^x^^2^+y^^2 | x^a^;1 |
| UEB (displayed) | e9<x9#b"6y9#b> | x9<a5#a> |
| UEB (embedded)* | e;9<x9#b"6y9#b> | x;9<a5#a> |
Nemeth In cases where a subscripted or superscripted expressions contains items that also carry subscripts or superscripts, the Nemeth code uses higher-order level indicators to help the reader keep track of the level relative to the baseline.
The Nemeth superscript with superscript indicator is (dots 45, 45). The superscript with subscript indicator is (dots 45, 56).
UEB The UEB uses the same indicators for all subscripts and superscripts, whether of first or higher order. It is assumed that the reader can keep track of the level. Note that grouping indicators are needed in both examples because even a single symbol carrying a subscript or superscript does not qualify as a single item.
Many thanks to the transcriber who found my UEB errors in the first draft of this page! Posted 5/4/2005.
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