exact a₁_hi_of_no_uflow_of_no_carry_of_lt_round
  npos hfaithful₁ hcorrect₁ hfa hfb hba no_uflow no_carry lt_round
case inr.inl.right.inl
round : ℕ → ℕ
n a b : ℕ
npos : 0 < n
hfaithful₀ : faithful₀ n round
hfaithful₁ : faithful₁ n round
hcorrect₁ : correct₁ n round
hfa : trunc n a = a
hfb : trunc n b = b
hba : b ≤ a
no_uflow : a + b ≥ 2 ^ n
lt_round : a + b < round (a + b)
no_carry : a + b < 2 ^ Nat.size a
⊢ trunc n (round (a + b) - (a + b)) = round (a + b) - (a + b)
no goals