[igraph] One-mode projection: Problem understanding increase of number of edges

[capitano . nemo]

Hello,

I have been scratching my head in trying to understand the result of a 
one-mode projection of a bipartite graph.

This is the bipartite graph

    > graph_bi
    IGRAPH DN-B 154625 448384 --

and after bipartite.projection(graph_bi) these are the two projections

    > graph_onemode$proj1
    IGRAPH UNWB 79186 13259012 --


    > graph_onemode$proj2
    IGRAPH UNWB 75439 50375826 --


Now, my intuition doesn't help here. Simply, How is possible that the 
number of edges in the two projections increases by 29 and 112 times 
respectively?

I am probably missing something here but as I understand the one-mode 
projection the number of edges should actually decrease. A-B and B-C 
(where A and C are type 1 nodes and B is a type 2 node) should be 
projected to A-C thus halving the number of edges...