Dixon's Hypergeometric Theorem/Proof 2

Proof
From Gauss's Hypergeometric Theorem, we have:
 * $\map F {a, b; c; 1} = \dfrac {\map \Gamma c \map \Gamma {c - a - b} } {\map \Gamma {c - a} \map \Gamma {c - b} }$

Therefore:

Therefore:

We now have:

Substituting $a = n$, $b = -x$ and $c = -y$, we obtain: