Well, just say that as y>1, -y<-1
Hence (x<3 && -y<-1) => x-y < 3-1=2
x<3, y>1 --> (implication) x-y<2
I know that this statement is true but I am having trouble approaching the proof. New to this statement stuff as I just recently started uni but I want to get implication proofs down pack ASAP. Thx in advance.