Problem #PRU-109909

Problems Set theory and logic Algorithm Theory Algorithm Theory
 10–12  2.0

Problem

Members of the State parliament formed factions in such a way that for any two factions \(A\) and \(B\) (not necessarily different)

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– also a faction (through

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the set of all parliament members not included in \(C\) is denoted). Prove that for any two factions \(A\) and \(B\), \(A \cup % \includegraphics{https://problems-static.s3.eu-west-2.amazonaws.com/production/task_images/700/109909-3.png} B\) is also a faction.