module Symbols;

import Stdlib.Data.Fixity open;
import Stdlib.Data.Nat open;

╘⑽╛ : Nat := suc 9;

-- no - function!?
- : Nat -> Nat -> Nat := (+);

（-） : Nat -> Nat -> Nat := (-);

（*） : Nat -> Nat -> Nat := (*);

syntax operator － additive;

－ : Nat -> Nat -> Nat := （-）;

syntax operator · multiplicative;

· : Nat -> Nat -> Nat := （*）;

（0） : Nat := ╘⑽╛ － ╘⑽╛ · zero;

主功能 : Nat := （0）;

axiom = : Type;

K : Nat → Nat → Nat
  | =a@zero =b := =a · =b
  | =a@(suc =b) == := =b · ==;