Consider the claim:(*) "Some porcupines are quadrupeds". What isthe converse of (*)? What is the obverse of (*)? What is the contrapositive of (*)?

Consider the claim: (*) "Some porcupines are quadrupeds".

What is the converse of (*)?

What is the obverse of (*)?

What is the contrapositive of (*)?

If all we know is that (*) is true, what do we know about the truth-values of (*)'s converse, obverse and contrapositive?

Now suppose all we know is that (*) is false. (Assume an Aristotelian interpretation of categorical claims.)

What do we know about the truth-value (i.e. true or false) of the corresponding A claim?

What do we know about the truth-value of the corresponding O claim?

What do we know about the truth-value of the corresponding E claim?