fact: Definition biv_horner_seqop2 : (int -> int -> R) -> int -> int -> R := foldr (fun a r u n k => let u' := fun n_ k_ : int => u n_ (int.shift 1%N k_) in r u' n k + biv_horner_seqop a u n k) (fun u n k => 0) cf.
imports: mathcomp(all_ssreflect all_algebra) shift bigopz