Let $V$ be a vector space. The set $W \subseteq V$ spans $V$ if for all $v \in V$, there exists $n \in \mathbb N$, a collection ${\alpha_i}{i=1}^n \subset \mathbb R$, and a collection ${v_i}{i=1}^n \subset W$ such that \(v = \sum_{i=1}^n \alpha_i v_i.\)
Wikidata ID: Q209812