function G = normpart(x)
% G = normpart(x) calculates the partial expectation of X at x, where
% X is N(0,1) random variable.
%
% G(x) = 1/sqrt(2*pi)* integral (t-x)*e^(-(t^2)/2)dt from x to inf.
%
% Written by Ulf Brannlund, April 23, 1993
G = normdens(x)-x*(1-normdist(x));