X + X \ar[r]^(.75){\epsilon_X} & X \\
Y_1 + Y_2 \ar[u]^{f'_1 + f'_2} \ar[ur]_{f}
} \]
-Then if we take $\eta_X = [id,id]$ we can define $f' = (f \circ i_1) + (f
-\circ i_2)$. This is unique and $\eta_X$ is natural by inspection.
+Then if we take $\epsilon_X = [id,id]$ we can define $f' = (f \circ i_1) + (f
+\circ i_2)$. This is unique and $\epsilon_X$ is natural by inspection.
\section{Right Adjoint}
\subsection{Unit}
(Y,Y) \ar[u]^{(f',f')} \ar[ur]_{(f_1,f_2)}
} \]
-Take $\eta_X = (\pi_1, \pi_2)$, then $f' = \ang{f_1, f_2}$. Uniqueness of
-$f'$ is immediate. Naturality of $\eta_X$ is immediate from the action of
+Take $\epsilon_X = (\pi_1, \pi_2)$, then $f' = \ang{f_1, f_2}$. Uniqueness of
+$f'$ is immediate. Naturality of $\epsilon_X$ is immediate from the action of
$\Delta\Pi$ on arrows:
\[ \xymatrix{
(A \times B, A \times B) \ar[r] \ar[d]^{\Delta \Pi f} & (A, B) \ar[d]^{f} \\