Index

0-skeleton

1-skeleton

2-skeleton

3-skeleton

This shows the skeleta of the simplex $\Delta_3$. The full simplex
is the set of points $(x_0,x_1,x_2,x_3)\in\mathbb{R}^4$ where
$x_0,x_1,x_2,x_3\geq 0$ and $x_0+x_1+x_2+x_3=1$. The $k$-skeleton
is the subspace where at least $3-k$ of the coordinates $x_i$ are
zero.

The $3$-skeleton consists of the full solid tetrahedron.