cases k
n k : Nat
⊢ getBit (n % 2 ^ k) zero = (decide (zero < k) && getBit n zero)
case zero
n : Nat
⊢ getBit (n % 2 ^ zero) zero = (decide (zero < zero) && getBit n zero)

case succ
n n✝ : Nat
⊢ getBit (n % 2 ^ succ n✝) zero = (decide (zero < succ n✝) && getBit n zero)