From: moritz Hilger (moritz.hilger_at_[hidden])
Date: 2006-09-07 05:18:52
> The problem is that add_edge() never clears boolvar - it is always true,
> even when I coerce redundant edges, as in the following code:
>
the problem is that your graph allows parallel edges, therefor the adding
always succeeds. you would have to check for existing edges via
out_edges(va).
cheers,
moritz