1-skeleton
= 1-skeleton
{title2=$X^{(1)}$}
= One-skeleton
{synonym}
The one-skeleton $X^{(1)}$ of a <CW complex> is the union of its zero-cells and one-cells. It is a graph. The unit-edge path metric measures the infimum of lengths of paths in this graph; it is different from metrics that allow paths through two-cell interiors.