Most dependently-typed languages support unicode.
Both adga and lean support unicode (in functions) and designing your custom operators. It's very useful to write proofs about math:
Here's a simple example from Lean:
lemma le_lim {x y : ℝ} {u : ℕ → ℝ} (hu : seq_limit u x)
(ineg : ∃ N, ∀ n ≥ N, y ≤ u n) : y ≤ x :=
begin
-- sorry
apply le_of_le_add_all,
intros ε ε_pos,
cases hu ε ε_pos with N hN,
cases ineg with N' hN',
let N₀ := max N N',
specialize hN N₀ (le_max_left N N'),
specialize hN' N₀ (le_max_right N N'),
rw abs_le at hN,
linarith,
-- sorry
end