The time symmetry inherent in the method reduces the level of local errors introduced into the integration by the discretization by removing all odd-degree terms, here the terms in Δ Δ t of degree three. The local error is quantified by inserting the exact values x ( t n − − 1 ) , x ( t n ) , x ( t n + 1 ) into the iteration and computing the Taylor expansions at time t = t n of the position vector x ( t ± ± Δ Δ t ) in different time directions: