a:=amb.future(joins,T("the","that","a"),T("frog","elephant","thing"));
b:=amb.future(joins,T("walked","treaded","grows"),T("slowly","squacking"));
c:=amb.future(joins,a,b);  // a future of futures
println(a,b,c);
c=c.noop();  // trigger the landslide, referencing c forces a result for a,b,c
println(a.noop(),b.noop(),c); // even though a has a result, it doesn't know it until we force it