Successive refinement on trees: a special case of a new MD coding region

New achievability results for the L-stage successive refinement problem with L>2 are presented. These are derived from a recent achievability result for the more general problem of multiple description (MD) coding with L>2 channels. It is shown that successive refinability on chains implies successive refinability on trees and that memoryless Gaussian sources are successively refinable on chains and trees.