[plt-scheme] efficient set implementation

Jefferson Heard skrev:

> AVL trees only support the set-union operation in O(n) time.  I haven't 
> checked galore for it yet, but I'd suspect that the author uses 
> something more efficient to represent sets, such as a binomial heap.  

In first Galore version (before PLaneT) there were severeal heap
implementations including binomial heaps. Since most people
only need one implementation, leftist heaps were picked, since
they are fast for most applications.

-- 
Jens Axel Søgaard