private double delayedLognormal(int time, double tau, double mean, double var) {
		double delay = time - tau;
		if(delay <= 0) return 0.0;
		else if(delay < 1) delay = 1;
		double denom = Math.sqrt(2*Math.PI*var) * delay;
		double gap = Math.log(delay) - mean;
		return Math.exp(-0.5*gap*gap/var)/denom;
	}