@article {DBLP:journals/scp/GiannottiMPT87, title = {Symbolic Evaluation with Structural Recursive Symbolic Constants}, journal = {Sci. Comput. Program.}, volume = {9}, number = {2}, year = {1987}, pages = {161-177}, author = {Fosca Giannotti and Attilio Matteucci and Dino Pedreschi and Franco Turini} }