grammar fixes

TQL

@@ -121,11 +121,10 @@ disk1_pool: storage pool back reference (eg: vg) [vmonly]
 disk1_voln: storage pool volume back reference (eg: ) [vmonly]
 
 == grammar ==
-input: prop EOL
+input: [ prop ] EOL
 prop: "(" prop ")" | stat
-stat: prop sep prop | prop mod word | close
-close: word [ op word ] | ¤
+stat: [ prop ] sep prop | [ prop ] mod word | clause
+clause: word [ op word ]
 sep: "&" | "|"
 mod: "^" | "%" | "$"
 op: "=" | "!=" |  ":" | "!:" | "~" | "!~" | ">" | ">=" | "<" | "<="
-¤: