SEPARABILITY BY SEMIVALUES MODIFIED FOR GAMES WITH COALITION STRUCTURE

Two games are inseparable by semivalues if both games obtain the same allocation whatever semivalue is considered. The prob-lem of separability by semivalues reduces to separability from the nullgame. For four or more players, the vector subspace of games insep-arable from the null game by semivalues contains games different tozero-game. Now, for five or more players, the consideration of a prioricoalition blocks in the player set allows us to reduce in a significantway the dimension of the vector subspace of games inseparable fromthe null game. For these subspaces we provide basis formed by gamesof a particular type