PVS problems with Redhat 9 or Enterprise PVS 3.1 was developed under Redhat 7.3, and has some incompatibilities in the libraries of Redhat 9 and Enterprise that require some adjustments to the 'pvs' shell script and disabling of ICS. First install everything as described in the INSTALL file. Copy the new "pvs" shell script from the top level of the CDROM (or get it from the FAQ section of the PVS website) over the one in PVSDIR, cd to PVSDIR, and run 'bin/relocate' to set the path. Then add the following line to your ~/.pvs.lisp file (create it if necessary). (setq *decision-procedures* (remove 'ics *decision-procedures*)) .