# Page 124

Location: Chapter 12, Exercise 5(a) at end of chapter

## It is (requirement on the bird)

$\Gamma xyzwv = y(zw)(xywv)$

## It should become

$\Gamma xyzwv = y(zw)(xyzwv)$

## Short explanation

The need for the missing variable in the definition can be confirmed by plugging in the solution for $$\Gamma$$ given a few pages later.