Abstract
The proton inclusive spectrum in the diffractive region is described by a triple-Pomeron term with no free parameters. Our input is the cross sections for the production of N*' s at CERN accelerator energies, which, according to duality rules for Pomeron-particle reactions, are related to the triple-Pomeron coupling via finite-mass sum rules. The extrapolated value of this coupling to t=0 induces rather weak constraints on the parameters of the Pomeron, and no sharp turnover of the proton spectrum near t=0 is expected.