Lower_bound
Definition
A set $A \subseteq \mathbb{R}$ is bounded below if there exists a lower bound $l \in \mathbb{R}$ satisfying $l \leq a\quad\forall a \in A$.
A set $A \subseteq \mathbb{R}$ is bounded below if there exists a lower bound $l \in \mathbb{R}$ satisfying $l \leq a\quad\forall a \in A$.