Can anyone guide me to some good books on discrete math for an engineering student? Our recommended book does not look too good and has some pretty bad reviews (Rosen, Discrete Math & Applications). It also costs $200. The problem is I still don't understand too well what the fundamentals of discrete math are, it seems like a related set of topics instead of being more distinct. In this case would it be better to supplement with texts on the individual fundamentals? Maybe good books on proofs, number theory etc.