\begin{equation}
    \begin{tikzpicture}[baseline={([yshift=-12pt]current bounding box.north)}]

        % BLANK DG
        \node[backtrack] (boxA) at (0, 0) {$$};
        \node[backtrack] (boxB) [right=1cm of boxA] {$$};
        \node[backtrack] (boxC) [right=1cm of boxB] {$$};
    
        \node[backtrackeq] (boxAeq) [below=-1pt of boxA] {$=$};
        \node[backtrackeq] (boxBeq) [below=-1pt of boxB] {$=$};
        \node[backtrackeq] (boxCeq) [below=-1pt of boxC] {$=$};
        
        \node[backtrack] (boxArev) [below=-1pt of boxAeq] {$$};
        \node[backtrack] (boxBrev) [below=-1pt of boxBeq] {$$};
        \node[backtrack] (boxCrev) [below=-1pt of boxCeq] {$$};
         
        \node (boxAr) at ([yshift=24pt,xshift=5mm]boxA) { };
        \node (boxBl) at ([yshift=24pt,xshift=-5mm]boxB) { };
        \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxAr)  --node[backtrackstep, above=3.0pt] {$$} (boxBl);
    
        \node (boxBr) at ([yshift=24pt,xshift=5mm]boxB) { };
        \node (boxCl) at ([yshift=24pt,xshift=-5mm]boxC) { };
        \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxBr)  --node[backtrackstep, above=3.0pt] {$$} (boxCl);
    
        \node (boxCrevl) at ([yshift=-24pt,xshift=-5mm]boxCrev) { };
        \node (boxBrevr) at ([yshift=-24pt,xshift=5mm]boxBrev) { };
        \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxCrevl)  --node[backtrackstep, below=3.0pt] {$$} (boxBrevr);
    
        \node (boxBrevl) at ([yshift=-24pt,xshift=-5mm]boxBrev) { };
        \node (boxArevr) at ([yshift=-24pt,xshift=5mm]boxArev) { };
        \draw [line width=0.4pt,-{Stealth[length=2mm]}] (boxBrevl)  --node[backtrackstep, below=3.0pt] {$$} (boxArevr);
        
    \end{tikzpicture}   
\end{equation}