English
When m = n and h' is a valid length extension, realizing castLE preserves realization: Realize of castLE φ equals realizing φ after composing xs with the cast.
Русский
При m = n и допустимом удлинении длины h' реализация castLE сохраняет реализацию: Realize castLE φ эквивалентна реализации φ после композиции xs с cast.
LaTeX
$$$ (\phi.castLE h').Realize v xs \iff \phi.Realize v (xs \circ Fin.cast h) $$$
Lean4
theorem realize_castLE_of_eq {m n : ℕ} (h : m = n) {h' : m ≤ n} {φ : L.BoundedFormula α m} {v : α → M}
{xs : Fin n → M} : (φ.castLE h').Realize v xs ↔ φ.Realize v (xs ∘ Fin.cast h) :=
by
subst h
simp only [castLE_rfl, cast_refl, Function.comp_id]