I think to remember something about being able to compute the fixed point of the function x -> x+1 (that is, a number for which this function returns the same n

I think to remember something about being able to compute the fixed point of the function x -> x+1 (that is, a number for which this function returns the same number). Our teacher showed us this function, and i think he also told us, curry reaction when people showed him this was something along the line of « well, that just means my theory is more powerful than yours, because it can express things yours can’t ». that was 20 years ago, but it made a big impression on me, so i think my memories are correct :)