>>12 補足
(参考)
https://www.math.nagoya-u.ac.jp/~nakamako/ Makoto Nakashima's web site
https://www.math.nagoya-u.ac.jp/~nakamako/Resources/Probability.pdf
確率論講義ノート
中島 誠 2019 年度版
(引用終り)

ここに戻る
このP11の「事象 A はほとんど確実に起こるといい,A, P-a.s.と書く. “ほとんど”という理由は A -“ ? で成り立つことがあるからである.」
a.s.＝Almost surelyだね

この”Almost surely”に対して
”Almost never describes the opposite of almost surely: an event that happens with probability zero happens almost never.[3]”
ってあるんやね

これ>>56の「確率的零事象」と同様の概念だが
このスレでの「確率的零事象」は、非正則分布の場合も含めて考えているので、正統な”Almost never”より少し広い概念を意味するのです

(参考)
https://en.wikipedia.org/wiki/Almost_surely
Almost surely
In probability theory, an event is said to happen almost surely (sometimes abbreviated as a.s.) if it happens with probability 1 (or Lebesgue measure 1).[1] In other words, the set of possible exceptions may be non-empty, but it has probability 0. The concept is analogous to the concept of "almost everywhere" in measure theory.

In probability experiments on a finite sample space, there is often[clarify] no difference between almost surely and surely (since having a probability of 1 often entails including all the sample points). However, this distinction becomes important when the sample space is an infinite set,[2] because an infinite set can have non-empty subsets of probability 0.

The terms almost certainly (a.c.) and almost always (a.a.) are also used. Almost never describes the opposite of almost surely: an event that happens with probability zero happens almost never.[3]

つづく