*Theorem: If T is any rooted tree with n nodes and e edges, then e = n - 1.*

My Base Case would be: If T is a one-node tree, then e = 0 and n = 1 so e = n - 1 is true.

Inductive Step: I should assume my IH which is the theorem itself, but how would I "write" it out? I cant seem to guide myself here.