Using truth tables to assess argument validity.

 

For each of the following proofs, construct a truth table in order to determine whether or not the proof is valid.

1. [ solution ]

1.av~a

2.(b<->c)->c    /.:b->~a

 

2. [ solution ]

1.~x

2.y->~(y->~y)

3.z<->(xvy)    /.:z&y

 

3. [ solution ]

1.d->e

2.~g->~e

3.d           /.:g

 

4. [ solution ]

1.s->(~rvw)

2.~r&s       /.:w

 

5. [ solution ]

1.~k->~m

2.~m->l

3.k->~l      /.:k<->m