MHB Putting a superscript before a variable or expression ....

[Math Amateur]

Can someone help with the issue/problem of placing a superscript before a variable or expression ... as Just and Weese do in their book on Set Theory ... in the expression for a Cartesian Product as follows:

View attachment 7536Hope that someone can help ...

Peter

 

[S.G. Janssens]

There are various packages that can do this and more sophisticated things, but I think in this case the easiest is: $^{A}B$. (Right-click on formula to see $\LaTeX$ source.)

 

[Opalg]

You may need to add an empty pair of braces before the superscript, like this: {}^{A}B. Otherwise, the superscript will attach itself to the previous element in the formula. Compare

$f\in ^I\left( \bigcup \{A_i:i\in I\}\right)$ with $f\in {}^I \left( \bigcup \{A_i:i\in I\}\right)$.

In the first case, the superscript $I$ has attached itself to the $\in$ symbol. Even when the braces are inserted, the superscript looks as though it is suspended halfway between the symbols on either side. You can eliminate that by inserting a negative space (given in TeX by \!) after the superscript, to get

$f\in {}^I \!\left( \bigcup \{A_i:i\in I\}\right)$.

 

[Math Amateur]

You may need to add an empty pair of braces before the superscript, like this: {}^{A}B. Otherwise, the superscript will attach itself to the previous element in the formula. Compare

$f\in ^I\left( \bigcup \{A_i:i\in I\}\right)$ with $f\in {}^I \left( \bigcup \{A_i:i\in I\}\right)$.

In the first case, the superscript $I$ has attached itself to the $\in$ symbol. Even when the braces are inserted, the superscript looks as though it is suspended halfway between the symbols on either side. You can eliminate that by inserting a negative space (given in TeX by \!) after the superscript, to get

$f\in {}^I \!\left( \bigcup \{A_i:i\in I\}\right)$.

Thanks to Krylov and Opalg for the help ...

Much appreciated ..

Peter