theorem shareFunction_le_one {w : Fin J → ℝ}
(hw : ∀ j, 0 ≤ w j)
(hpos : 0 < ∑ k : Fin J, w k) (j : Fin J) :
shareFunction w j ≤ 1 := by
have hsum := shareFunction_sum_one (ne_of_gt hpos)
calc shareFunction w j
≤ ∑ k : Fin J, shareFunction w k :=
Finset.single_le_sum (fun k _ => shareFunction_nonneg hw k) (Finset.mem_univ j)
_ = 1 := hsumTen Views of a Single Object: