[math-fun] Tree terminology

11 Jul 2012

      Speaking of terminology, I¹m drawing a blank:

Tree is to Composition
  AS
X is to Partition

X  ==  ...?

For example the following are distinct Trees, but equivalent X¹s:

    O           O
   / \         / \
  O   O       O   O
 / \   \     /   / \
O   O   O   O   O   O

Thanks!
  --MLB

Marc LeBrun