Definition:Half-Plane/Closed/Left

Definition
Let $\PP$ be a Cartesian plane.

Let $\LL$ be the $y$-axis.

The closed left half-plane $\HH_{\text {CL} }$ is the area of $\PP$ on the left of and including $\LL$.

That is, where $x \le 0$:


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

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