>>770
>>よりよく分かったわ。ありがと

ありがとね
最小値原理は、多分超限帰納法でも使えるんだわ
で、ノイマンが、正則性公理を置いた意図が、それだという（下記）
それが、今回よく分かったよ

お礼に、一つヒントを追加しておくが
>>771（dccを満たす証明について） は
無限列にしか意味ないよ
有限列なら、自明だから
珍説に対するヒントな

(参考)
https://en.wikipedia.org/wiki/Axiom_of_regularity
Axiom of regularity
However, regularity makes some properties of ordinals easier to prove; and it not only allows induction to be done on well-ordered sets but also on proper classes that are well-founded relational structures such as the lexicographical ordering on {(n,α )| n∈ ω ∧ α is an ordinal }
Given the other axioms of Zermelo?Fraenkel set theory, the axiom of regularity is equivalent to the axiom of induction. The axiom of induction tends to be used in place of the axiom of regularity in intuitionistic theories (ones that do not accept the law of the excluded middle), where the two axioms are not equivalent.
(引用終り)
以上