apple-0.1.0.0: math/hypergeometric.apple

λa.λb.λz.
{
  rf ← [(*)/ₒ 1 (𝒻 x (x+y-1) (⌊y))]; fact ← rf 1;
  Σ ← λN.λa. (+)/ₒ 0 (a'(⍳ 0 N 1)); Π ← [(*)/x];
  Σ 30 (λn. {nn⟜ℝ n; (Π ((λa.rf a nn)'a)%Π((λb. rf b nn)'b))*(z^n%fact nn)})
}