# MATH introduce sugar for let
# if would be good to introduce desugarings more rigorously, but for now...
# ... just a very vague sketch
[hear] (intro let);
[hear] (= (let ((x 10)) (+ (x) 5))
((? x / + (x) 5) 10));
[hear] (= (let ((x 10) (y 5)) (+ (x) (y)))
(((? x / ? y / + (x) (y)) 10) 5));