The empty string Ø is the root vertex of T2 and for a vertex x of T2 the string x0 is the left child of x and the string x1 is the right child of x in T2.
One Tree Hill | One Tree Hill (TV series) | tree | Christmas tree | Herbert Beerbohm Tree | Porcupine Tree | The Joshua Tree | The Hanging Tree | Quebracho tree | Joshua Tree National Park | Under the Yum Yum Tree | Happy Tree Friends | binary | Tree of Life | Tree of Knowledge | tree line | Tree | Oak Tree | tree of life | Tea Tree Plaza Interchange | Rockin' Around the Christmas Tree | Radial tree | Joshua Tree | The Tree | The Learning Tree | The Juniper Tree | The Casuarina Tree | Peepal Tree Press | Our Father Who Art in The Tree | Lost Monarch (tree) |