Most extensively utilized half-spaces:
The most extensively utilized half-spaces (unbounded) are:
Planar Half-space
H = {(x, y, z) : z < 0}
Cylindrical Half-space
= {(x, y, z) : x2 + y2 < R2
Spherical Half-space
H = {(x, y, z) : x2 + y2 + z2 < R2}
Conical Half-space
H = {(x, y, z) : x2 + y2 [tan (x / 2) z]2}
Toroidal Half-space
H = {(x, y, z) : (x2 + y2 + z2 - R22 - R12)2 < 4R22 (R12 - z2)}