\begin{tikzpicture}[x=1cm,y=1cm]
\begin{scope}
  \fill[foldblue!8] (0,0) ellipse[x radius=.3,y radius=.86];
  \coordinate (a0) at (0,.55);
  \coordinate (a1) at (0,-.55);
  \foreach \j in {0,1,2}
    \coordinate (b\j) at (1.75,{.9-.9*\j});
  \foreach \i in {0,1}
    \foreach \j in {0,1,2}
      \draw[fold edge] (a\i)--(b\j);
  \foreach \i in {0,1}
    \draw[marked edge] (a\i)--(b0);
  \foreach \i in {0,1}{
    \node[part A] at (a\i) {};
    \node[font=\small,anchor=east] at (-.12,{.55-1.1*\i}) {$a_{\i}$};
  }
  \foreach \j in {0,1,2}{
    \node[part B] at (b\j) {};
    \node[font=\small,anchor=west] at (1.85,{.9-.9*\j}) {$b_{\j}$};
  }
  \node[diagram label] at (.85,-1.65) {$H=K_{2,3}$};
\end{scope}
\node[font=\Large] at (2.85,0) {$=$};
\begin{scope}[shift={(3.7,0)}]
  \coordinate (r) at (0,0);
  \foreach \j in {0,1,2}{
    \coordinate (rb\j) at (1.75,{.9-.9*\j});
    \draw[fold edge] (r)--(rb\j);
  }
  \draw[marked edge] (r)--(rb0);
  \node[part A] at (r) {};
  \node[font=\small,anchor=north east] at (-.05,-.05) {$\mathbf0$};
  \foreach \j in {0,1,2}{
    \node[part B] at (rb\j) {};
    \node[font=\small,anchor=west] at (1.85,{.9-.9*\j}) {$p(b_{\j})$};
  }
  \node[diagram label] at (.85,-1.65) {$R=K_{1,3}$};
\end{scope}
\node[font=\Large] at (6.85,0) {$\otimes$};
\begin{scope}[shift={(7.7,0)}]
  \coordinate (fa0) at (0,.55);
  \coordinate (fa1) at (0,-.55);
  \coordinate (fb) at (1.75,0);
  \foreach \i in {0,1}{
    \draw[marked edge] (fa\i)--(fb);
    \node[part A] at (fa\i) {};
    \node[font=\small,anchor=east] at (-.12,{.55-1.1*\i}) {$a_{\i}$};
  }
  \node[part B] at (fb) {};
  \node[font=\small,anchor=west] at (1.85,0) {$b_0$};
  \node[diagram label] at (.85,-1.65) {$F=K_{2,1}$};
\end{scope}
\end{tikzpicture}