The sequence space of all real-valued sequences, denoted $Seq(\mathbb{R})$, is typically investigated through the lens of infinite-dimensional vector spaces, utilizing Banach space norms or Schauder bases. This work proposes a complementary, constructive classification based instead on the asymptotic limit profile encoded by the pair $(\liminf a_n, \limsup a_n)$. We demonstrate that this perspective naturally partitions $Seq(\mathbb{R})$ into seven mutually disjoint macroscale blocks, covering behaviors from finite convergence to bounded and unbounded oscillation. For each block, we provide explicit closed-form representative sequences and establish that every constituent class possesses the cardinality of the continuum. Furthermore, we investigate the structural relationships between these blocks at two distinct levels of granularity. At the macroscale, we employ injective mappings to define an idealized connectivity graph, while at the microscale, we introduce a connection relation governed by the Hadamard (pointwise) product. This dual analysis reveals a rich directed graph structure where the block of finite convergent sequences functions both as the only block subspace and as a global attractor with no outgoing connections. Statistical comparisons between the idealized and realized adjacency matrices indicate that the pointwise product structure realizes approximately two-thirds of the theoretically possible macroscale relations. Ultimately, this partition-based framework endows the seemingly chaotic space $Seq(\mathbb{R})$ with a transparent, geometrically interpretable internal structure.
翻译:所有实值序列构成的序列空间,记作 $Seq(\\mathbb{R})$,通常通过无限维向量空间的视角进行研究,利用巴拿赫空间范数或绍德尔基。本文提出了一种互补的、构造性的分类方法,该方法基于由有序对 $(\\liminf a_n, \\limsup a_n)$ 编码的渐近极限轮廓。我们证明,这一视角自然地将 $Seq(\\mathbb{R})$ 划分为七个互不相交的宏观尺度区块,覆盖了从有限收敛到有界及无界振荡的行为。对于每个区块,我们提供了显式的闭式代表序列,并证明了每个构成类都具有连续统的基数。此外,我们在两个不同的粒度层次上研究了这些区块之间的结构关系。在宏观尺度上,我们采用单射映射来定义一个理想化的连通图;而在微观尺度上,我们引入了一个由阿达玛(逐点)积支配的连接关系。这种双重分析揭示了一个丰富的有向图结构,其中有限收敛序列区块既作为唯一的块子空间,又作为一个没有出连接的全局吸引子。理想化邻接矩阵与实现邻接矩阵之间的统计比较表明,逐点积结构实现了大约三分之二理论上可能的宏观尺度关系。最终,这种基于划分的框架为看似混沌的空间 $Seq(\\mathbb{R})$ 赋予了一种透明且几何可解释的内部结构。