Yahoo patents granted on 13 December 2011

4 US patents granted on 13 December 2011 and assigned to Yahoo

1 8,078,645 Operations on multi-level nested data structure
2 8,078,642 Concurrent traversal of multiple binary trees
3 8,078,638 Operations of multi-level nested data structure
4 8,078,149 Advertising information display method, and advertising information display system