>>120-128
ふっふ、ほっほ
出かけていました

5ｃｈ便所板らしいなぁ〜ｗ

アホとバカが大きな顔をして
自分たちはバカですと、騒ぐ

数学の情報は、英語が日本語の十倍という人がいる
いまの場合も、該当するよなｗ

下記で
”assuming the axiom of countable choice, a set is countable if its cardinality (the number of elements of the set) is not greater than that of the natural numbers.”
google訳
”可算選択公理を前提とすると、集合の濃度（集合の要素の数）が自然数の濃度より大きくない場合、その集合は可算です。有限でない可算集合は可算無限であると言われます。”

これ
百回音読してね ；ｐ）

(参考)
https://en.wikipedia.org/wiki/Countable_set
Countable set
In mathematics, a set is countable if either it is finite or it can be made in one to one correspondence with the set of natural numbers.[a] Equivalently, a set is countable if there exists an injective function from it into the natural numbers; this means that each element in the set may be associated to a unique natural number, or that the elements of the set can be counted one at a time, although the counting may never finish due to an infinite number of elements.

In more technical terms, assuming the axiom of countable choice, a set is countable if its cardinality (the number of elements of the set) is not greater than that of the natural numbers.
A countable set that is not finite is said to be countably infinite.