. The solution S to be constructed and its cost f(S) are initialized to ![ $$\\varnothing $$ ](A000000_0_En_0_Chapter_IEq0.gif) and 0, respectively, in lines 0 and 0. In line 0, the set ![ $$\\mathcal{F}$$ ](A000000_0_En_0_Chapter_IEq0.gif) of 