!!
%+ mul 3 (add 1 1)

the forms mix freely: an irregular call as one tall argument.

glossary

%+ calls a gate that takes two arguments.

%+(add 2 3) is 5.

irregular forms:

(gate a b) is %+(gate a b)

mul multiplies two atoms.

(mul 3 4) is 12.

%: 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)

add sums two atoms.

(add 2 3) is 5.