"Saturn has rings and Neptune is windy, or Jupiter is massive"

Question

1."Either Salvador Dali or Pablo Picasso ignored perspective, but it is not the case that both of them did."

2."Greg dreams of both Ferraris and Porsches." 

3."Saturn has rings and Neptune is windy, or Jupiter is massive"

4."Gary Trudeau penned humorous cartoons if and only if Jane Pauley conducted incisive interviews." 

Answer 1

1) SD xor Pp

2) F and P

3) S and N or J

4)Gt <--> Jp