[Jprogramming] why 0 0&$ instead of 0&$ ?

[Michal Wallace]

The standard verb 'echo' is defined as ( 0 0&$@(1!:2&2) )

The ( 0 0&$ ) obviously throws away the result so it's not echoed in the
REPL.

But why ( 0 0 ) instead of just ( 0 ) ?