%
% sI01INFAA  The integral I_{0,[1,inf]}(a,a) in
%    variable-precision arithmetic
%
function y=sI01infaa(dig,a)
digits(dig);
if subs(a)<=0
  error('a not in range')
  return
end
p=feval(symengine,'psi',a,1);
psi=vpa(p);
y=a*psi-1;
