Hi.

I'm having trouble with this 'show' this question.

Show that any rooted tree with at least two vertices contains a non-terminal

vertex such that all of its children are terminal vertices.

I can see why this is the case visually. Quite logical in fact. How do I show that the children of the two vertices are actually terminal vertices. Drawing it out is a piece of cake, but showing it in words... its a different story!!

Any help would be great!