(~~~) :: S x -> S x -> Bool
(S1D x) ~~~ (S1D y) = norm_Inf (x - y) < 0.00001
(~~~) :: S x -> S x -> Bool
(S1D x) ~~~ (S1D y) = norm_Inf (x - y) < 0.00001
(S1D x) ~~~ (S1D y) = norm_Inf (x - y) < 0.00001