Read guard of the form !(x) in neverclaims.
So far all neverclaims encountered would use (!(x)), but the files from the Büchi store do not. * src/neverparse/neverclaimscan.ll: Accept ! in front of guard, so that we can read Promela files from Goal's Büchi store. * src/tgbatest/neverclaimread.test: Test it.