English
Independence of {x, y} is equivalent to independence of {y, x}.
Русский
Независимость множества {x, y} эквивалентна независимости множества {y, x}.
LaTeX
$$$\\mathrm{LinearIndependent}_R(\\![x,y\\]) \\iff \\mathrm{LinearIndependent}_R(\\![y,x\\])$$$
Lean4
/-- Also see `LinearIndependent.pair_iff'` for a simpler version over fields. -/
theorem pair_iff : LinearIndependent R ![x, y] ↔ ∀ (s t : R), s • x + t • y = 0 → s = 0 ∧ t = 0 :=
by
rw [← linearIndepOn_univ, ← Finset.coe_univ, show @Finset.univ (Fin 2) _ = {0, 1} from rfl, Finset.coe_insert,
Finset.coe_singleton, LinearIndepOn.pair_iff _ (by trivial)]
simp