RULE XIIISUPERSCRIPTS AND SUBSCRIPTS
Level Indicators Base Line"
 Superscript^
 Superscript with Superscript^^
 Superscript with Subscript^;
 Superscript with Superscript with Superscript^^^
 Superscript with Superscript with Subscript^^;
 Superscript with Subscript with Superscript^;^
 Superscript with Subscript with Subscript^;;
 Subscript;
 Subscript with Superscript;^
 Subscript with Subscript;;
 Subscript with Superscript with Superscript;^^
 Subscript with Superscript with Subscript;^;
 Subscript with Subscript with Superscript;;^
 Subscript with Subscript with Subscript;;;
§71. Nature of Superscripts and Subscripts: It is characteristic of mathematical expressions to employ signs, usually in smaller type, which are elevated or depressed relative to the base line. A sign which is elevated relative to the base line is called a superscript; one which is depressed relative to the base line is called a subscript. When an entire expression is at the superscript or subscript level, it should be written without an indicator in braille, but its position must be explained to the reader by a transcriber's note.
§74. Orientation by Level Indicator:
b. The effect of a level indicator with two components may be analyzed as follows:
c. The effect of a level indicator with three components may be analyzed as follows:
verbose semantics 
n Superscript
x Super Superscript
y Super Super Superscript
z Super Super Super Superscript
diagonal ellipsis 

verbose semantics 
n Subscript
x Sub Subscript
y Sub Sub Subscript
z Sub Sub Sub Subscript
diagonal ellipsis 

verbose semantics 
Integral Subscript
0 Superscript
StartRoot
1 minus x squared EndRoot
Baseline
f leftparenthesis x rightparenthesis d x 

verbose semantics 
x Subscript
n minus 1 comma n minus 1 Baseline
comma x Subscript
n minus 1 comma n Baseline
comma x Subscript
n comma n minus 1 

verbose semantics 
Upper
A Superscript
n plus n plus n ellipsis to m n apostrophe s Baseline
equals a Superscript
m n 

verbose semantics 
10 Superscript
3 plus largedash Baseline
is equal to 10 Superscript
5 Baseline
period 

verbose semantics 
leftparenthesis 1 minus sine squared x rightparenthesis squared equals cosine Superscript
4 Baseline
x 

h. Any symbol or situation other than those in a to g preserves the level that is already in effect.
verbose semantics 
x Superscript
leftparenthesis m Super Superscript
n Superscript
rightparenthesis 

??!??
verbose semantics 
t rightbracket Subscript
t equals a Superscript
t equals b Baseline
equals b minus a 

verbose semantics 
Upper
P 1 Superscript
alpha 1 Baseline
ellipsis Upper
P Subscript
r Superscript
alpha Super Subscript
r 

verbose semantics 
leftparenthesis 1 minus sine squared x rightparenthesis squared cosine squared x 

§81. NonUse of Level Indicators:
verbose semantics 
StartLayout Enlarged leftbrace
1st Row
u equals x squared
2nd Row
v equals x squared plus y squared
Enlarged rightbrace EndLayout


c. A level indicator must not be used before any closing grouping symbol which is drawn in.
§82. Simultaneous and NonSimultaneous Superscripts and Subscripts:
§83. Primes in Addition to Superscripts or Subscripts:
a. The prime symbol must never be preceded by the superscript indicator.
c. For primes in other roles see §172.