# Categorical Prepositions Converse, Inverse, Obverse, Contrapositive YouTube Lecture Handouts

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## Categorical Prepositions Converse, Inverse, Obverse, Contrapositive

- Obverse will always be valid form
- Converse is not valid in A & O
- Contrapositive is not valid in E & I

Cases –

- All S is P
- Converse – All P is S
- Obverse – No S is non P
- Contrapositive All non P is non S

- Obverse will always be valid form
- Converse is not valid in A & O
- Contrapositive is not valid in E & I

Cases –

- All S is P
- Converse – All P is S
- Obverse – No S is non-P
- Contrapositive all non P is non S
- Valid if P exists
- Converse of A - Some P is S
- Converse of E – Some P is not S

-Manishika