case true =>
  have : ∀ b, f false b = b := by intro b; cases b <;> assumption
  simp [this]
f : Bool → Bool → Bool
f_stable : f false false = false
n : Nat
hft : f false true = true
⊢ getBit (if true = true then n else 0) 0 = f false (getBit n 0)
no goals