Talk:Index finite lists of positive integers

Sets or lists?

"It is known that the set of finite lists of positive integers is countable"
I know that the set of finite sets of positive integers is countable.
What is a list? If it is something like the example Perl is using "12 11 0 7 9 15 15 5 7 13 5 5", which is not a set, I don't think these are countable.--Nigel Galloway (talk) 12:57, 8 September 2018 (UTC)