“…At first, the theory of the Weierstrass points was developed only for smooth curves, and for their canonical divisors. In the last years, starting from some papers by R. Lax and C. Widland (see [10], [11], [12], [13], [14], [18]), the theory has been reformulated for Gorenstein curves, where the invertible dualizing sheaf substitutes the canonical sheaf. In this contest, the singular points of a Gorenstein curve are always Weierstrass points.…”