Conversion is the simplest operation to perform. All you do is switch the subject and predicate term . You must remember that conversion is only valid for E and I statements. I remember that conversion is valid for E and I statements by looking at the name of the operation. You must replace the predicate term with its complement .
All cats are non-dogs.
Contraposition is easier to perform than obversion, although it also involves a two-step process. You can only validly contrapose A and O statements. You replace both the subject and predicate terms with their complements . To make an inference on the basis of such an operation is to commit a logical fallacy. Venn diagrams These are used as they were in the last section , with some modifications to accomodate term compliments .