deletions | additions       diff --git a/layout.md b/layout.md  index 12edcb4..b2b9ae0 100644  --- a/layout.md  +++ b/layout.md 
...
Labeled_arrays_Python_X_Ray__.md  Columnar_containers_Columnar_containers_are__.md  N_Dimensional_Data_Frames_Note__.md  Graph_structures_A_simple_graph__.md Abstractions_Graph_structures_A_simple__.md  Resilient_Distributed_Datasets__.md  Implementation_specific_the_NumPy_ndarray__.md  Implementation_specific_the_R_data__.md