In the notes attached I have quite a few problems with one of the proofs. In the proof of the proposition on p15,
a) he goes from
I understand how these two lines are equal but how can we change the 's to 's in going from eqn 25 to the defn of ?
b) where does eqn 27 come from? isn't
is it something like if we compose the numerator with then we have to cancel that out by composing the with to give the ? I don't really get why this is allowed though?
c)Where does eqn 29 come from?
When can you expect yours?