Endpoints of a path (chain)

Endpoints of a path (chain) --- концевые вершины пути (цепи).

For a given path (chain) [math]\displaystyle{ P_{m} = v_{1},v_{2} \cdots v_{m} }[/math], vertices [math]\displaystyle{ v_{1} }[/math] and [math]\displaystyle{ v_{m} }[/math] are the endpoints of that path (chain).