Abstract
We summarize several inequalities for the neutron and proton inelastic structure functions W2(ν,Q2) that must be satisfied if the partons are identified with quarks. Some of these inequalities provide us with very useful constraint equations for the P(N) function of the parton model. Due to lack of sufficient data, it is not certain at present if all the inequalities are satisfied. The importance of these inequalities lies in the fact that if any of them are confirmed not to satisfy the experimental data, the concept of individual quark-parton association has to be abandoned.