%: calls a gate with several arguments, gathering them into one sample.

%:(add 2 3) is 5.

irregular forms:

(gate a b c) is %:(gate a b c)

fall unwraps a unit, or gives a default on ~.

(fall ~ 7) is 7.

some wraps a value in a unit - [~ value].

(some 5) is [~ 5].