| word ^"!::=" alternatives /ws
alternatives ::= equiAlt +/ (ws ">" ws)
-equiAlt ::= conjuncts +/ (ws "|" ws) => "alternatives"
+equiAlt ::= conjuncts +/ (ws "|" ws)
sequence ::= es
> es ws ^"/" e
| "\r"
an ::= [a-zA-Z0-9_]
word ::= an++
-quoted ::= "\"" (([~\"\\] | escaped)*) "\"" => "sify"
+quoted ::= "\"" (([~\"\\] | escaped)+) "\""
+ | "\"\"" => ""
escaped ::= "\\n" => "\n"
| "\\r" => "\r"
| "\\" [~nr]