H. Yang, A.P. Petropulu, X. Yang and T. Camp, ?ALLIANCES with Optimal Relay Selection,"IEEE Trans. on Vehicular Technology, January 2008. (MATLAB Code)
People have vast background knowledge to cope with everyday situations.
We don t have to be told everything explicitly because we can call on the background knowledge.
We use `default knowledge to handle situations where knowledge is incomplete.
This is called common sense reasoning.