=/ pins a named value (a face) into the subject for the lines below it.

name=value optionally declares the type.

=/(a 3 (add a a)) is 6.

:* 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)

=. changes one face in the subject, leaving the rest, for the lines below.

=/(a [p=1 q=2] =.(p.a 9 a)) is [p=9 q=2].