930 (Both are 2-morphisms from $(a\bullet \id_y)\bullet b$ to $a\bullet b$.)

   930 (Both are 2-morphisms from $(a\bullet \id_y)\bullet b$ to $a\bullet b$.)

   931 \begin{figure}[t]

   931 \begin{figure}[t]

   932 \begin{align*}

   932 \begin{align*}

   933 \mathfig{0.4}{triangle/triangle4a} \\

   933 \mathfig{0.4}{triangle/triangle4a} \\

   934 \mathfig{0.4}{triangle/triangle4b} \\

   934 \mathfig{0.4}{triangle/triangle4b} \\

   935 \mathfig{0.4}{triangle/triangle4c} 

   936 \mathfig{0.4}{triangle/triangle4c} 

   936 \end{align*}

   937 \end{align*}

   937 \nn{remember to change `assoc' to $\alpha$}

   938 \nn{remember to change `assoc' to $\alpha$}

   938 \caption{Ingredients for the triangle axiom.}

   939 \caption{Ingredients for the triangle axiom.}

   939 \label{fig:ingredients-triangle-axiom}

   940 \label{fig:ingredients-triangle-axiom}