Definition:Half-Plane/Closed/Left

Definition
Let $P$ denote the plane implemented as a Cartesian system.

Let $L$ be the $y$-axis.

The closed left half-plane $H_{\text {CL} }$ is the area of $P$ on the left of and including $L$.

That is, where $x \le 0$:


 * $H_{\text {CL} } := \set {\tuple {x, y}: x \in \R_{\le 0} }$

Also see

 * Definition:Closed Right Half-Plane


 * Definition:Closed Upper Half-Plane
 * Definition:Closed Lower Half-Plane


 * Definition:Open Left Half-Plane
 * Definition:Open Right Half-Plane


 * Definition:Open Upper Half-Plane
 * Definition:Open Lower Half-Plane