We give a simple proof of an isomorphism between the two
C[t]-modules: the module of relative cohomologies Λ2/dH∧Λ1 and the module of Abelian integrals corresponding to a regular at
infinity polynomial H in two variables. Using this isomorphism, we prove
existence and deduce some properties of the corresponding Picard-Fuchs system.Comment: A separate section discusses Fuchsian properties of the Picard-Fuchs
system, Morse condition exterminated. Few errors were correcte