Rose (n-ary) trees with both upwards- (i.e. cached) and downwards-traveling (i.e. accumulating) monoidal annotations.

abstractly, a dualtree is a rose (n-ary) tree with data at leaves, data at internal nodes, and two types of monoidal annotations, one travelling "up" the tree and one traveling "down".

this package provides the documentation for a library for the haskell programming language. see http://www.haskell.org/ for more information on haskell.