Belmonte, Matthew2007-04-232007-04-231988-06http://techreports.library.cornell.edu:8081/Dienst/UI/1.0/Display/cul.cs/TR88-920https://hdl.handle.net/1813/6760Efficient implementations for two optimisations to Knuth's attribute grammar circularity test are described. A new method for eliminating useless visits to productions is introduced. This improves upon a somewhat weaker mechanism introduced previously by Deransart et. al. Data structures and algorithms for graph covering and elimination of redundant unions are discussed and proven correct.978471 bytes347983 bytesapplication/pdfapplication/postscripten-UScomputer sciencetechnical reporttechnical report