GitLab

replaced first name by initials

Updated with SoCG format. There is a line number restriction this year. We have to fit everything within 500 lines. Currently, we are at 602. 

- small typos
- def of $l_{i,j}$
- removed $i(H)$, 
- reintroduced the definition of tree decomposition (T,b)

Replacing the tree-decomposition by clique-sum operations. 
Introduction of clique-sum extendable representation.
Replacing treewidth by k-trees