English
For x,y ∈ PiLp 1 β, the nonnegative distance equals the sum of coordinatewise nonnegative distances: nndist(x,y) = ∑_i nndist(x_i,y_i).
Русский
Для x,y ∈ PiLp 1 β, расстояние в NNReal-части равно сумме NNReal-расстояний координат: nndist(x,y) = ∑_i nndist(x_i,y_i).
LaTeX
$$$\operatorname{nndist}(x,y) = \sum_{i\in ι} \operatorname{nndist}(x_i,y_i),\quad x,y\in PiLp\;1\;β$$$
Lean4
theorem nndist_eq_of_L1 (x y : PiLp 1 β) : nndist x y = ∑ i, nndist (x i) (y i) :=
NNReal.eq <| by push_cast; exact dist_eq_of_L1 _ _