1. The problem statement, all variables and given/known data Consider the following question Adams is a boy who does not own a car. Mary dates only boys who own cars.Therefore Mary does not date Adams. 2. Relevant equations 3. The attempt at a solution My answer is like this... Let Bx=x is a boy. Ox=x owns car Dxy=x Dates y a=Adams m=Mary Accordingly we can translate sentences as 1)Ba&~Oa 2)for all x (Bx&Ox->Dmx) ----------------------- 2) can be written as Ba&Oa->Dma (by universal specification) further 2 can be reduced to 3) Ba->(Oa->Dma) (By law of exportation) 4) Oa->Dma (from p->q and p so q) 5) ~Oa (From p&q so q) So, "we cant conclude that Mary does not date Adams". Am i wrong? If i'm please explian me where it went wrong. Thanks in advance.