\newcommand\skeinrelationscale{0.30}
	\begin{tikzpicture}[scale = \skeinrelationscale]
		\tikzstyle{every node} = [font = \small]
		\foreach \x in {0}
		{
			\foreach \y in {-8}
			{

				\draw[black,thick,->] (\x-7,\y-2) -- (\x+6,\y-2);
				
				\draw (\x-6,\y-2) .. controls (\x-4,\y-0) and (\x+1,\y-0) .. (\x+3,\y-2);
				\draw (\x-4,\y-2) .. controls (\x-2,\y-0) and (\x+3,\y-0) .. (\x+5,\y-2);
				

				\foreach \t in {9,11,18,20}
				{
					\fill (-15+\t,\y-2) circle (.15);

				}
				\fill (\x-6,\y-2) node[below]{\tiny $i$};
				\fill (\x-4,\y-2) node[below]{\tiny $i+1$};
				\fill (\x+2,\y-2) node[below]{\tiny $i+m$};
				\fill (\x+6,\y-2) node[below]{\tiny $i+m+1$};
				
				
				\draw(\x+10, \y-1) node[] {$=$};
			}
		}
		\end{tikzpicture}%\\
%\vspace{0.5mm}
\begin{tikzpicture}[scale = \skeinrelationscale]
		\tikzstyle{every node} = [font = \small]
		\foreach \x in {0}
		{
			\foreach \y in {-8}
			{
				\draw[black,thick,->] (\x-7,\y-2) -- (\x+6,\y-2);

				
				
				\draw (\x-6,\y-2) .. controls (\x-5.5,\y-1.5) and (\x-4.5,\y-1.5) .. (\x-4,\y-2);
				\draw (\x+3,\y-2) .. controls (\x+3.5,\y-1.5) and (\x+4.5,\y-1.5) .. (\x+5,\y-2);
				

				\foreach \t in {9,11,18,20}
				{
					\fill (-15+\t,\y-2) circle (.15);

				}
				\fill (\x-6,\y-2) node[below]{\tiny $i$};
				\fill (\x-4,\y-2) node[below]{\tiny $i+1$};
				\fill (\x+2,\y-2) node[below]{\tiny $i+m$};
				\fill (\x+6,\y-2) node[below]{\tiny $i+m+1$};
		\draw (\x+10, \y-1) node[] {$+$};
			}
		}
		\end{tikzpicture}
\quad
    \begin{tikzpicture}[scale = \skeinrelationscale]
		\tikzstyle{every node} = [font = \small]
		\foreach \x in {0}
		{
			\foreach \y in {-8}
			{
				\draw[black,thick,->] (\x-7,\y-2) -- (\x+6,\y-2);

				
				\draw (\x-6,\y-2) .. controls (\x-5,\y+1) and (\x+4,\y+1) .. (\x+5,\y-2);
				\draw (\x-4,\y-2) .. controls (\x-3,\y-1) and (\x+2,\y-1) .. (\x+3,\y-2);
				

				\foreach \t in {9,11,18,20}
				{
					\fill (-15+\t,\y-2) circle (.15);

				}
				\fill (\x-6,\y-2) node[below]{\tiny $i$};
				\fill (\x-4,\y-2) node[below]{\tiny $i+1$};
				\fill (\x+2,\y-2) node[below]{\tiny $i+m$};
				\fill (\x+6,\y-2) node[below]{\tiny $i+m+1$};
			}
		}
    \end{tikzpicture}