Do the same (as in Set C) for each of the following:

No metal is friable that has been properly tempered. No brass is properly tempered unless it is given an oil immersion. Some of the ashtrays on the shelf are brass. Everything on the shelf is friable. Brass is a metal. Therefore some of the ashtrays were not given an oil immersion. ( Mx: x is metal; Fx: x is friable; Tx: x is properly tempered; Bx: x is brass; Ox: x is given an oil immersion; Ax: x is an ashtray; Sx: x is on the shelf)