I found Wolfram uses f-¹(x): http://mathworld.wolfram.com/InverseFunction.html
It would be nice to simplify the page to f-¹(x) ... but in the intro I say "So the inverse of: 2x+3 is: (y-3)/2" and that does not sit well with using f-¹(x)
Nor with the table of inverses as ganesh mentions.
With the rise of social media people spend a lot of time on Facebook, Twitter, Instragram, Snapchat. They are the online version of sports stadiums and shopping malls.
We are more like a Parisian Cafe. We have our regulars, who can often be seen dining here and discussing with their friends, and also people who just pop in for a coffee or pastry.