@inproceedings{Seidl99Guarding, author = {Helmut Seidl and Andreas Neumann}, title = {On {G}uarding {N}ested {F}ixpoints}, booktitle = {Computer Science Logic}, editor = {J\"org Flum and Mario Rodr\'iguez-Artalejo}, month = {September}, year = 1999, pages = {484-498}, series = {Lecture Notes in Computer Science}, volume = {1683}, publisher = {Springer}, address = {Madrid, Spain}, }