Post #2734926

Lesson learned: It can be crusial to remember that a nullary function f is a function that takes no arguments and not a function applied to the empty set as argument. Depending on how you write your mathematics it can therefore be useful to have distinct notation for the nullary tuple () even if it is undertood to be the empty set Ø. This way you will be less likely to accidentally confuse f() with f(Ø). Lesson learned from mistakes in the litterature.