#                                 987654321
@carry0 = (1,2)   , $carry0 =        vec(11)
@carry1 = (3)     , $carry1 =      vec(0100) 
@carry2 = (5,6,7) , $carry2 =   vec(1110000) 
@carry3 = (8,9)   , $carry3 = vec(110000000)