No CrossRef data available.
Published online by Cambridge University Press: 17 October 2016
Here we present a simplification of one of the standard proofs that . We then look at extensions of the new approach, and add comments on the nature of the simplification (which relates to Step 1 below) and finally on the literature.
As in most proofs of the result, we shall actually prove that ; because
this is equivalent to the result sought.