-- Pi, lambda
let a: Πx: bool. bool = λx. x;

-- Multiplication, both OK
let b: bool ✖ bool × bool = (1, 1, 1);

-- Sigma
let c: Σx: bool. bool = bla;

-- Arrows
let d: bool → bool = split
 { True _ ⇒ False 0
 | False _ ⇒ True 0
 };