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Subcontraries
 I and O
 If one is False, the other must be True
 CANT both be false

Superalternation
 A has corresponding I
 Ehas corresponding O
 The superaltern implies the TRUTH of its corresponding subaltern

Contradictories
 Cant both be True
 Cant both be False
 A  O
 E  I

Contraries
 Cant both be True
 If one is true, the other must be False
 But if one is False, then we can infer nothing about the other

Conversion
 Replace the subject and Predicate (just switch)
 Only works for E and I statements
 No S are P = No P are S
 O and A statements cant work (except by lim.)

Convert by Limitation
 Turn A statements into I statements
 All Sare P = Some P are S
 Still just switch the S and P
 Only works for A statemets
 One way inference

Subcontraries
 I, O
 Cant both be False
 Can both be True

Sub alternation
 If one is true you can immediately infer the other is True
 A > I
 E > O
 If A or E is False, then their corresponding subalterns are undetermined

Obversion
 Used in all statements
 Change quality of proposition (affirmative/Negative)
 Replace predicate term with its complement
 A: all s are p  E: No S are non p
 E: No s are p  A: all s are non p
 I: some s are p  O: some s ar notnonp
 O: Some s is not pI:some s is non p

Contraposition
 replace the subject term with the complement of the predicate term
 Replace the predicate term with the complement of its subject term
 Not all contrapositives are valid

Contrapositive by lim.
 works only for E statements
 E > O

