Hacker News Reader

I can't seem to figure out what you mean by inverse. Is the inversion of addition subtraction? Neither post seems to explain what it is (or maybe it assumes knowledge of ⊥ and ⊤?)

View on HN

Given a function F that accepts an argument x and returns y, its inverse is another function which, when passed y will return x.

For dyadic functions, the incerse argument is always the right side one.

So negation is its own inverse.

So the inverse of 2+ is indeed subtraction of 2.

Reply on news.ycombinator.com