14 ms·
>{f ∈ [1..N ⟶ 1..N] : ∀ y ∈ 1..N : ∃ x ∈ 1..N : f[x]=y} is not expert-level material.
by VyseofArcadia 10y ago
>{f ∈ [1..N ⟶ 1..N] :
∀ y ∈ 1..N : ∃ x ∈ 1..N : f[x]=y}
is not expert-level material.
- lacampbell 10y agoDidn't read the article, is that supposed to show the properties of a function that is both "1:1" and "onto"? Ie, the set of all inputs is the same as as the set of possible outputs, so for any x in the set, f(x) will return a result that is also in the set? Didn't major or minor in mathematics but I took a few papers. Time to the read the article and collect my prize or look ignorant under my real name on the web. EDIT: I was wrong! Though in my defense I had been given the context from TFA I think I would have got it.
- deleted 10y ago[deleted]