cases hfft : f false true
case refl
f : Bool → Bool → Bool
f_stable : f false false = false
n : Nat
⊢ (if f false true = true then n else 0) % 2 = if f false (decide (n % 2 = 1)) = true then 1 else 0
case refl.false
f : Bool → Bool → Bool
f_stable : f false false = false
n : Nat
hfft : f false true = false
⊢ (if false = true then n else 0) % 2 = if f false (decide (n % 2 = 1)) = true then 1 else 0

case refl.true
f : Bool → Bool → Bool
f_stable : f false false = false
n : Nat
hfft : f false true = true
⊢ (if true = true then n else 0) % 2 = if f false (decide (n % 2 = 1)) = true then 1 else 0