Generalities
Integral pointsLet π : U → Spec(O S ) be a flat scheme over O S with generic fiber U. An integral point on U is a section of π; the set of such points is denoted U(O S ).In the sequel, U will be the complement to a reduced effective Weil divisor D in a normal proper scheme X , both generally flat over Spec(O S ). Hence an S-integral point P of (X , D) is a section s P : Spec(O S ) → X of π, which does not intersect D, that is, for each prime ideal p ∈ Spec(O S ) we have s P (p) / ∈ D p . We denote by X (resp. D) the corresponding generic fiber. We generally assume that X is a variety (i.e., a geometrically integral scheme);