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

        \node[backtrack] (boxA) at (0, 0) {$<<boxA>>$};
        \node[backtrack] (boxB) [right=1cm of boxA] {$<<boxB>>$};
        \node[backtrack] (boxC) [right=1cm of boxB] {$<<boxC>>$};
    
        \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] {$<<stepAB>>$} (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] {$<<stepBC>>$} (boxCl);
        
    \end{tikzpicture} 
\end{equation}