=> sets the subject to its head, then evaluates its tail against it.

=>([a=1 b=2] b) is 2.

:* makes a tuple of many elements, nesting to the right.

:*(1 2 3) is [1 2 3].

irregular forms:

[a b c d] is :*(a b c d)

^= binds a name (a face) to a value - the name=value you see in samples and pins.

^=(a 5) is 5, labeled a.

irregular forms:

a=b is ^=(a b)