rw [Nat.add_mod, mod_ulp₁, Nat.zero_add, Nat.mod_mod]
round : ℕ → ℕ
n a b : ℕ
npos : 0 < n
hfaithful₁ : faithful₁ n round
hfa : trunc n a = a
hfb : trunc n b = b
hba : b ≤ a
no_carry : a + b < 2 ^ Nat.size a
round_le : round (a + b) ≤ a + b
size_eq : Nat.size (a + b) = Nat.size a
ulp_eq : ulp n (a + b) = ulp n a
mod_ulp₁ : a % ulp n a = 0
⊢ (a + b) % ulp n a = b % ulp n a
no goals