  In a full-duplex 3-way $\Delta$ channel, three transceivers communicate to
each other, so that a number of six messages is exchanged. In a $Y$-channel,
however, these three transceivers are connected to an intermediate full-duplex
relay. Loop-back self-interference is suppressed perfectly. The relay forwards
network-coded messages to their dedicated users by means of interference
alignment (IA) and signal alignment. A conceptual channel model with cyclic
shifts described by a polynomial ring is considered for these two related
channels. The maximally achievable rates in terms of the degrees of freedom
measure are derived. We observe that the Y-channel and the 3-way $\Delta$
channel provide a $Y$-$\Delta$ product relationship. Moreover, we briefly
discuss how this analysis relates to spatial IA and MIMO IA.
