\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.3) arc (180:0:1mm) -- (-.4,0);
	\draw (-.2,0) -- (-.2,.5);
	\draw (.4,0) -- (.4,.5);
	\draw (.6,0) -- (.6,.5);	
	\node at (.1,.4) {...};
	\node at (0,0) (T) [rectangle, draw, fill=white] {$\hspace{4mm} T \hspace{4mm}$};
\end{tikzpicture}
=
\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.3) arc (180:0:1mm) -- (-.4,0);
	\draw (-.2,0) -- (-.2,.5);
	\draw (.4,0) -- (.4,.5);
	\draw (.6,0) -- (.6,.5);	
	\node at (.1,.4) {...};
	\node at (0,0) (T) [rectangle, draw, fill=white] {$\hspace{4mm} T' \hspace{4mm}$};
\end{tikzpicture}
\, , \,
\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.5);
	\draw (-.4,0) -- (-.4,.3) arc (180:0:1mm) -- (-.2,0);
	\draw (.4,0) -- (.4,.5);
	\draw (.6,0) -- (.6,.5);	
	\node at (.1,.4) {...};
	\node at (0,0) (T) [rectangle, draw, fill=white] {$\hspace{4mm} T \hspace{4mm}$};
\end{tikzpicture}
=\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.5);
	\draw (-.4,0) -- (-.4,.3) arc (180:0:1mm) -- (-.2,0);
	\draw (.4,0) -- (.4,.5);
	\draw (.6,0) -- (.6,.5);	
	\node at (.1,.4) {...};
	\node at (0,0) (T') [rectangle, draw, fill=white] {$\hspace{4mm} T' \hspace{4mm}$};
\end{tikzpicture}
\, , \ldots , \,
\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.5);
	\draw (-.4,0) -- (-.4,.5);
	\draw (-.2,0) -- (-.2,.5);
	\draw (.4,0) -- (.4,.3)  arc (180:0:1mm) -- (.6,0);
	\node at (.1,.4) {...};
	\node at (0,0) (T) [rectangle, draw, fill=white] {$\hspace{4mm} T \hspace{4mm}$};
\end{tikzpicture}
=\begin{tikzpicture}[baseline]
	\draw (-.6,0) -- (-.6,.5);
	\draw (-.4,0) -- (-.4,.5);
	\draw (-.2,0) -- (-.2,.5);
	\draw (.4,0) -- (.4,.3)  arc (180:0:1mm) -- (.6,0);
	\node at (.1,.4) {...};
	\node at (0,0) (T') [rectangle, draw, fill=white] {$\hspace{4mm} T' \hspace{4mm}$};
\end{tikzpicture}