-ec ::= [~\]\\\-\~] | escaped
-
-alternatives ::= equiAlt +/ (ws ">" ws)
-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 ^"+/" e /ws
+alternatives ::= (Conjuncts +/ (ws "|" ws)) +/ (ws ">" ws)
+
+Conjuncts ::= Sequence
+ | Sequence ^"&" e*/ws /ws
+ | Sequence ^"&~" e*/ws /ws
+
+ps ::= e*/ws => "ps"
+ | (e+/ws ws)? "^" Quoted (ws e+/ws)? => "ps2"
+psy ::= ps
+ | ps wp ^"/" ws e
+psx ::= psy => "psy"
+ | e "<-" psy /ws => "psyl"
+ | psy "->" e /ws => "psyr"
+ | e "<-" psy "->" e /ws => "psylr"
+Sequence ::= Quoted => "qprod"
+ > psx
+ | psx "=>" ^"[]" /ws
+ | psx ^"=>" (word|Quoted) /ws
+
+ec ::= ~[\-\]\\]
+ | escaped
+
+Range ::= ec => "range"
+ | ec ^"-" ec
+
+e ::= word => "nonTerminal"
+ | Quoted => "literal"
+ | ^"()"
+ | ^"{" Sequence "}" /ws
+ | ^"[" Range* "]"
+
+ | (e ^"++" /ws > e ^"+" /ws)
+ | (e ^"++/" e /ws > e ^"+/" e /ws)
+ | (e ^"**" /ws > e ^"*" /ws)
+ | (e ^"**/" e /ws > e ^"*/" e /ws)