On the Fran？a and Hama analysis of elastic hadron scattering

after reviewing the main aspects of the model-independent analysis on elastic proton-proton scattering, developed by fran？a and hama in the seventies, we argue that the work can be considered a paradigm for empirical analysis on elastic hadron interactions (the inverse problem). we discuss some further developments, consequences and results that have been recently obtained on the subject and which have been based on the original strategy by fran？a and hama.