re **Puzzle 281**

Going from left to right we have three main blocks:

\$$\qquad\Phi \otimes 1_b : a \otimes b \to (c \otimes d) \otimes b\$$

\$$\qquad1_c \otimes \Psi : c \otimes (d \otimes b) \to c \otimes (e \otimes f)\$$

\$$\qquad\Theta \otimes 1_f : (c \otimes e) \otimes f \to g \otimes f\$$

These don't quite match up, so we need associators to plug the gaps:

\$$\qquad\alpha_{c, d, b} : (c \otimes d) \otimes b \to c \otimes (d \otimes b)\$$

\$$\qquad\alpha^{-1}_{c, e, f} : c \otimes (e \otimes f) \to (c \otimes e) \otimes f\$$

So the composite morphism is:

\$$\qquad(\Theta \otimes 1_f) \circ \alpha^{-1}_{c, e, f} \circ (1_c \otimes \Psi) \circ \alpha _{c, d, b} \circ (\Phi \otimes 1_b) : a \otimes b \to g \otimes f\$$