r der for each nest ing level is shown

r der for each nest ing level is shown here in a sim pli fied form ( Sn is the start level num ber, En is the cor re spond ing end level num ber): S1 E1 Single level S1 S2 E2 E1 Double level S1 S2 S3 E3 E2 E1 Triple level Copyright 2005, […]