  This paper looks into the $K$-user interference channel. Interference
Alignment is much likely to be applied with double-layered symbol extensions,
either for constant channels in the H$\o$st-Madsen-Nosratinia conjecture or
slowly changing channels. In our work, the core idea relies on double-layered
symbol extensions to artificially construct equivalent time-variant channels to
provide crucial \textit{channel randomness or relativity} required by
conventional Cadambe-Jafar scheme in time-variant channels
\cite{IA-DOF-Kuser-Interference}.
