In mathematics, a Hamiltonian path in a graph is a path that visits each vertex precisely once. A Hamiltonian cycle is a cycle which visits each vertex once and only once.
This type of path is named after William Rowan Hamilton who invented a puzzle, now known as Hamilton's puzzle, about the construction of such paths.
... that Vronsky is about to propose to her.
The following morning Stiva and Vronsky are at the station to welcome Anna and Vronsky's mother respectively. This is ...