table T(bitstring).

free a: bitstring.
free c: channel.

event bad.
query event(bad).

process
	insert T(a); get T(=a) in 0 else event bad

(* EXPECTPV
RESULT not event(bad) cannot be proved.
0.004s (user 0.000s + system 0.004s), max rss 7180K
END *)
