set preciseLetExpand = false.

const a,b: channel.

reduc f(a) = b.

event e2.

query event(e2) ==> false.

process
     out((event e2; a), let x = f(b) in b)


(* EXPECTPV
RESULT not event(e2) is false.
0.004s (user 0.000s + system 0.004s), max rss 7208K
END *)
