A disjunctive sequence is a sequence in which every finite string appears. A normal sequence is disjunctive, but a disjunctive sequence need not be normal. A rich number in base b is one whose expansion in base b is disjunctive:[9] one that is disjunctive to every base is called absolutely disjunctive or is said to be a lexicon. A number normal in base b is rich in base b, but not necessarily conversely. The real number x is rich in base b if and only if the set {xbn mod 1 : n ∈ N} is dense in the unit interval.

https://en.wikipedia.org/wiki/Normal_number#Definitions

【 在 pEaklAUrEL 的大作中提到: 】
: 是不是等价的？
:
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FROM 123.113.25.*