Cleaner syntax?

I've written an alternative parser for Morte with less symbols using `binder:type body` for λ, `binder-type body` for ∀. If you ignore λ's, ∀'s and arrows, and allow empty binders, you get something quite similar. For example, `Zero`, which currently is `λ(a : *) → λ(succ : a → a → a) → λ(zero : a) → zero`, could be written as `λ a : * -> λ succ : (-a -a a) -> λ zero : a -> zero`. But you can also drop those symbols and add line breaks:

a: *
succ: -a -a a
zero: a
zero

Another example, `List.map`:

u: * # from type
v: * # to type
f: -u v # function to map
l: (List u) # mapped list
a: *
cons: -v -a a
nil: a
(l a (h:u (cons (f h))) nil)

IMO that looks cleaner.