cases decide (i ≥ k) <;> simp [f_stable]
case a
f : Bool → Bool → Bool
f_stable : f false false = false
m n k i : Nat
⊢ (decide (i ≥ k) && f (getBit m (i - k)) (getBit n (i - k))) =
    f (decide (i ≥ k) && getBit m (i - k)) (decide (i ≥ k) && getBit n (i - k))
no goals