const a,b: channel.

reduc f(a) = b.

event e2.

query event(e2) ==> false.

process
     out((event e2; a), f(b))


(* EXPECTPV
RESULT not event(e2) is false.
0.000s (user 0.000s + system 0.000s), max rss 7200K
END *)
