



A GraphBased Definition of Distillation Geoff Hamilton and Gavin MendelGleason,
In this paper, we give a graphbased definition of the distillation transformation algorithm. This definition is made within a similar framework to the positive supercompilation algorithm, thus allowing for a more indepth comparison of the two algorithms. We find that the main distinguishing characteristic between the two algorithms is that in positive supercompilation, generalization and folding are performed with respect to expressions, while in distillation they are performed with respect to graphs. We also find that while only linear improvements in performance are possible using positive supercompilation, superlinear improvements are possible using distillation. This is because computationally expensive terms can only be extracted from within loops when generalizing graphs rather than expressions.
