fact: Definition derivable (f : V -> W) a v := cvg ((fun h => h^-1 *: ((f \o shift a) (h *: v) - f a)) @ 0^').
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum matrix interval) mathcomp(mathcomp_extra boolp classical_sets functions) reals signed topology prodnormedzmodule normedtype landau forms