@article{Arbib_Manes_1978, title={Tree transformations and the semantics of loop-free programs}, volume={4}, url={https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3161}, number={1}, journal={Acta Cybernetica}, author={Arbib, Michael Anthony and Manes, Ernest Gene}, year={1978}, month={Jan.}, pages={11-17} }