omit updates on eval of all-linear node locations
omit updates on eval of all-linear node locations

darcs-hash:20060126054437-1a7c6-f3ce3ddd6d186db38543fe954bd8303f5bc49b9c

kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc,kirbyfan64/jhc