Paul needs to read and write some documents. In the following, assume the system security policy is described completely by the Bell$-$LaPadula model. Note that the situation described may be impossible, in which case you should say so and show why.

Please give the least clearance that Paul can have if he wishes to read a document with classification $($ SECRET, $\{$ NUC, EUR $\})$ and a document with classification $($ CONFIDENTIAL, $\{$ ASI $\}).$

Please give the greatest clearance that Paul can have if he wishes to write to a document with classification $($ TOP SECRET, $\{$ EUR $\})$ and a document with classification $($ SECRET, $\{$ EUR, NUC $\}).$

Please give the greatest clearance that Paul must have if he wishes to read a document with classification $($ SECRET, $\{$ EUR, NUC $\}),$ to write a document with classification $($ CONFIDENTIAL, $\{$ NUC, EUR $\}),$ and to read another document with classification $($ TOP SECRET, $\{$ ASIA, EUR $\}).$