Software engineering has to reconcile modularity with efficiency. One way to grapple with this dilemma is to automatically transform a modular-speci- fied program into an efficient-implementable one. This is the aim of deforesta- tion transformations which get rid of intermediate data structures constructio- ns that appear when two functions are composed. Nevertheless, existing functional methods cannot deforest non-trivial intermediate constructions that are processed by symbolic composition. This new deforestation technique is based on the descriptional composition dedicated to attribute grammars. In this paper, we present the symbolic composition, we outline its counterpart in terms of classical deforestation methods and we sketch a way to embed it in a functional framework.