%%%------------------------------------------------------------------------------------------------------------ \begin{tikzpicture} \begin{scope}
\node [anchor=center,draw,fill=red!20,minimum height=1.8em,minimum width=2.5em] (h) at (0,0) {${\mathbi{h}}^{k-1}$}; \node [anchor=west,draw,fill=blue!20,minimum height=1.8em,minimum width=2.5em] (s) at ([xshift=6em]h.east) {${\mathbi{s}}^{k}$}; \node [anchor=west,draw,fill=green!20,minimum height=1.8em,minimum width=2.5em] (h2) at ([xshift=6em]s.east) {${\mathbi{h}}^{k}$};
\node [anchor=east] (prev) at ([xshift=-2em]h.west) {...}; \node [anchor=west] (next) at ([xshift=2em]h2.east) {...}; \draw [->,thick] ([xshift=0.1em]prev.east) -- ([xshift=-0.1em]h.west);
\draw [->,thick] ([xshift=0.1em]h.east) -- ([xshift=-0.1em]s.west) node [pos=0.5,above] {\scriptsize{${\mathbi{s}}^k = {\mathbi{h}}^{k-1}{\mathbi{W}}^k$}}; \draw [->,thick] ([xshift=0.1em]s.east) -- ([xshift=-0.1em]h2.west) node [pos=0.5,above] {\scriptsize{${\mathbi{h}}^k = f^k({\mathbi{s}}^{k})$}};
\draw [->,thick] ([xshift=0.1em]h2.east) -- ([xshift=-0.1em]next.west); \end{scope} \end{tikzpicture} %%%------------------------------------------------------------------------------------------------------------
