Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
a) An SPR move example. The subtree P is pruned from the initial comprehensive tree and regrafted into branch R. b) An example of an NNI move around an inner branch e. Two subtrees, one from each side of the inner branch, are selected, pruned, and interchanged. The NNI move is a special case of the SPR move.
