Please do 8,10,11,12 only (please do it the way i solved one of the problems)

Philosophy (introduction to formal logic)

These questions need to be proven by models where you use universal discourse, extension and refs

For example, for Pa---> ~Qb

You need to do write (contingent) first the prove like this

false true

UD={Jack, Bob} UD={Jack, Bob}

Ext (P)={Jack} Ext (P)=0

Ext (Q)={Bob} Ext (Q)=0

Ref (a)=Jack Ref (a)=Jack

Ref (b)= Bob Ref (b)=Bob

Directions Determine whether each of the following sentences is contingent a tautology, or a contradiction. Show your work with models Directions Determine whether the following sets of sentences are consistent Show your work with models Directions Determine whether the following pairs of sentences are logically equivalent. Show your work with models Directions Determine whether each of the following sentences is contingent a tautology, or a contradiction. Show your work with models Directions Determine whether the following sets of sentences are consistent Show your work with models Directions Determine whether the following pairs of sentences are logically equivalent. Show your work with models