-equiAlt ::= conjuncts +/ (ws "|" ws) => "alternatives"
-
-sequence ::= Es
- > Es ^"/" e /ws
-Es ::= e+
-//es ::= E+/ws
-
-conjuncts ::= rewrite
- | rewrite ^"&" sequence /ws
- | rewrite ^"&~" sequence /ws
-
-rewrite ::= sequence /ws => "rewrite"
- | sequence ^"=>" word /ws
- | sequence ^"=>" quoted /ws
- | sequence "=>" "()" /ws => "wrap"
-
-range ::= ec => "range0" | ec ^"-" ec => "range0"
-e ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" alternatives "}" /ws
- | "[" [\~]? range* "]" => "range"
- | e ^"*/" e /ws
- | e ^"+/" e /ws
- | e ^"?" /ws
- | e ^"~/~" /ws