20. Univ. is "persons". The phrase "never talk" is merely a stronger form of "are persons who do not talk". The Proposition may be written "All | fully occupied persons | are | persons who do not talk about their grievances". 21. Univ. is "riddles". The phrase "if they can be solved" is equivalent to the Attribute "that can be solved". The Proposition may be written "No | riddles that can be solved | are | riddles that interest me". § 2. _Method of Diagrams._ _Solutions for § 4, Nos. 1-12._ SL4-A ·---------------· ·-------· 1. No m are x'; | | (O)| | | | All m' are y. | ·---|---· | |---|---| | | | | | | |(O)| |(I)|---|---|---| ·-------· | |(O)|(O)| | | ·---|---· | .'. No x' are y'. | | (O)| ·---------------· pg137 ·---------------· ·-------· 2. No m' are x; |(O) | (O)| | | | Some m' are y'. | ·---|---· | |---|---| | | | | | | |(I)| |---|---|---|---| ·-------· | | | | | | ·---|---· | .'. Some x are y'. | | (I)| ·---------------· ·---------------· ·-------· 3. All m' are x; |(O) | (I)| | |(I)| All m' are y'. | ·---|---· | |---|---| | | | | | | | | |---|---|---|---| ·-------· | | | | | | ·---|---· | .'. Some x are y'. |(O) | (O)| ·---------------· ·---------------· 4. No x' are m'; | | (O)| All y' are m. | ·---|---· | | | | | | |---|---|(I)|---| There is no Conclusion. | | | | | | ·---|---· | |(O) | (O)| ·---------------· ·---------------· ·-------· 5. Some m are x'; | | | | | | No y are m. | ·---|---· | |---|---| | |(O)| | | | |(I)| |---|---|---|---| ·-------· | |(O)|(I)| | | ·---|---· | .'. Some x' are y'. | | | ·---------------·