English
The nth symmetric power distributes over intersection: the nth symmetric power of s ∩ t is equal to the intersection of the nth symmetric powers.
Русский
Симметрическая мощность n-го порядка сохраняет пересечение: (s ∩ t)^{(n)} = s^{(n)} ∩ t^{(n)}.
LaTeX
$$$ (s \\cap t)^{(n)} = s^{(n)} \\cap t^{(n)} $$$
Lean4
@[simp]
theorem sym_inter (s t : Finset α) (n : ℕ) : (s ∩ t).sym n = s.sym n ∩ t.sym n :=
by
ext m
simp only [mem_inter, mem_sym_iff, imp_and, forall_and]