% -*- texinfo -*-
% @deftypefn {Mapping Function} {} beta (@var{a}, @var{b})
% For real inputs, return the Beta function,
% @tex
% $$
% B (a, b) = {\Gamma (a) \Gamma (b) \over \Gamma (a + b)}.
% $$
% @end tex
% @ifnottex
%
% @example
% beta (a, b) = gamma (a) * gamma (b) / gamma (a + b).
% @end example
% @end ifnottex
% @end deftypefn