# question mark operator.
# local operations.
resource qm2()
	op g() {send}
	op f() {send}
	send g()
	write( ? f, ? g)
	send f()
	send g()
	send f()
	send g()
	write( ? f, ? g)
	while (?f + ?g > 0) {
		# give preference to f
		in f() -> write("in f",?f,?g)
		[] g() and ?f == 0 -> write("in g",?f,?g)
		ni
	}
end
