Sort

[zben at umcp-cs.UUCP]

The technical term for a sort that preserves the pre-existing order of
records that compare equal is a "stable" sort.  This type of sort is
required for some applications.
The recent confusion over the terms "preorder", etc stems from a 
terminology change.  The forms of tree traversal used to be called
"preorder", "postorder", and "endorder".  About halfway through my
undergraduate computer science education they were changed to
"preorder", "inorder" and "postorder".  The older terms describe more
fully the action taken at each node, but the newer terminology is more
descriptive of the "big picture", what you are doing to the entire tree.
(Reminds me of the summer they renumbered every room on campus!)
Ben Cranston