English
The Real embedding preserves the sum of a multiset: (s.sum)^\uparrow = (s.map (\uparrow)).sum.
Русский
Преобразование Real сохраняет сумму мультимножества: (s.sum)^\uparrow = (s.map (\uparrow)).sum.
LaTeX
$$$ (s.sum \\\\text{ : }\\\\mathbb{R}_{\\\\ge 0})^{\\\\uparrow} = (s.map (\\\\uparrow)).\\\\text{sum}. $$$
Lean4
@[norm_cast]
theorem coe_list_prod (l : List ℝ≥0) : ((l.prod : ℝ≥0) : ℝ) = (l.map (↑)).prod :=
map_list_prod toRealHom l