I am trying to use the regular expression feature from TexStudio but somehow I can't get it to work and i couldn't find an example or an explanation in the manual.
I am trying to replace variables
y1,y2,y3 (y1) with
x_1,x_2,x_3 (x_1). In the tip from 'Reg' it is mentioned that 'You can use \1 to \9 in the replace text to insert a submatch.'
I tried to Replace it like this but now everything is replaced with (x_\1) and not the corresponding number. What am I doing wrong?
In adddition: is there a regular expression for all numbers? (1 as well as 1999) For letters there is [A-Z], but [0-9999] only gets the first digit marked.