simp
case refl
f : Bool → Bool → Bool
f_stable : f false false = false
m : Nat
hm : ¬m = 0
⊢ getBit
      (if 0 = 0 then if f true false = true then m else 0
      else
        if f (decide (m % 2 = 1)) (decide (0 % 2 = 1)) = true then
          bitwise f (m / 2) (0 / 2) + bitwise f (m / 2) (0 / 2) + 1
        else bitwise f (m / 2) (0 / 2) + bitwise f (m / 2) (0 / 2))
      0 =
    f (getBit m 0) (getBit 0 0)
case refl
f : Bool → Bool → Bool
f_stable : f false false = false
m : Nat
hm : ¬m = 0
⊢ getBit (if f true false = true then m else 0) 0 = f (getBit m 0) false