Function L
	L(t | m, s, t0) - deviation of activity from a longer- term trend over the period from t0 to t. L(t | m, s, t0) = N(t | m,s) - N(t | m,t-s-t0) ´ s/(t-s-t0 )
		Usually t0 is the beginning of the catalog.
				Sixth Workshop on Non-Linear Dynamics and Earthquake Prediction The Abdus Salam ICTP, Miramare
	16/10/2001							7