下記英文をば 英語では Sequence、列 infiniteで ”a singly infinite sequence or a one-sided infinite sequence” と ”doubly infinite sequence”、”bi-infinite” とあるよ
まあ、低レベルでは理解難しいよな 無理するな
https://en.wikipedia.org/wiki/Sequence Sequence
Finite and infinite The length of a sequence is defined as the number of terms in the sequence.
Normally, the term infinite sequence refers to a sequence that is infinite in one direction, and finite in the other-the sequence has a first element, but no final element. Such a sequence is called a singly infinite sequence or a one-sided infinite sequence when disambiguation is necessary. In contrast, a sequence that is infinite in both directions-i.e. that has neither a first nor a final element-is called a bi-infinite sequence, two-way infinite sequence, or doubly infinite sequence. A function from the set Z of all integers into a set, such as for instance the sequence of all even integers ( ..., -4, -2, 0, 2, 4, 6, 8, ... ), is bi-infinite. This sequence could be denoted {\displaystyle (2n)_{n=-∞〜 ∞}.
