In proximity theory, we use \delta
and \ll
as binary relations on the power set of a set X. How can one display NOT \delta
or NOT \ll
similar to how we can do \not\in
. Using \not\delta
and \not\ll
place the strike-through in bad positions over the \delta
and \ll
.
For NOT \delta
, I am currently using
\!\!\not\!\delta
For NOT \ll
, I am using
\hskip 0.4mm \not \hskip -0.4mm \ll
There are a few problems here. Sometimes the placement of the "not" over the "delta" is a little off but it varies throughout the pages. Also, at the end of the line, I may get the \not
appearing at the end of the current line and the \delta
appearing at the beginning of the next line. I have not noticed this issue with my defininition of NOT \ll
.
What is the best way to define these symbols? How can one make sure that the "not" is on the same line as the "delta"?
Best Answer
Just use Heiko Oberdiek's
centernot
package: