Logic Conversion, Conversion by Limitation, Obversion, Contraposition

(Conversion) All S are P

All P are S

(Obvert) No S are P

All S are non P

(Contraposition) All S are P

All non P are non S

How to do an obversion with particular type propositions

First change the copula (are to are not or are not to are), then negate the predicate

How to do an obversion with universal type propositions

First change the quantity (all becomes no or no becomes all), then negate the predicate

How to do an E-type conversion by limitation

First do a conversion (No P are S), then do an implication using the square of opposition (Some P are not S)

How to do an A-type conversion by limitation

First give the implication according to the square of opposition (Some S are P), then do a conversion (Some P are S)

What is the long hand way to do contraposition

First give the obvert answer, then convert, then obvert again

(Conversion) No S are P

No P are S

(Obvert) All S are P

No S are non P

(Contraposition) No S are P

No non P are non S

(Conversion by Limitation) All S are P

Some P are S

(Conversion) Some S are P

Some P are S

(Conversion by Limitation) No S are P

Some P are not S

(Conversion) Some S are not P

Some P are not S

(Obvert) Some S are not P

Some S are non P

(Obvert) Some S are P

Some S are not non P

(Contraposition) Some S are P

Some non P are non S

(Contraposition) Some S are not P

Some non P are not non S

How to do a conversion

Switch the Subject and the Predicate

What is the short hand way to do contraposition

Switch the subject and the predicate, then negate both