function tplus = tplus(ld, a, prec)
arguments
    ld
    a
    prec = 32;
end
    p = 1/(ld-1);
    q = (2-ld)/(2*ld-2);
    fun = @(x) (1 - x.^2).^q ./ ...
        sqrt(p * (1 - x.^2) .* hypergeom([-p+1 1], 2, x.^2) + a);
    tol = 10^(-prec);
    tplus = vpa(2/(ld-1) * ...
        vpaintegral(fun, 0, 1, 'RelTol', tol, 'AbsTol', 0), prec);
end