# Missing brackets
ipv4-addr:value = '1.2.3.4'
# Unterminated string
[ipv4-addr:value = '1.2.3.4]
# Missing operator
[file:name 'x']
# Missing object type
[:value = 'x']
# Bad qualifier (missing SECONDS)
[file:name='a'] WITHIN 60
# Trailing tokens
[file:name='a'] [file:name='b']
# Empty observation
[]
# Dangling AND
[file:name='a'] AND
# Unknown character
[file:name = @]
