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The Square of Opposition

 

Contraries (A and E):  cannot both be true but could both be false.

Subcontraries (I and O): cannot both be false but could both be true.

Contradictories (A and OE and I):  have opposite truth values.

Subalternation (A and IE and O): the superaltern implies the subaltern.




Details of the Square of Opposition are provided in the lecture notes.


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