-s ::= w* Grammar w* => "gram"
-Grammar ::= R+ => "grammar"
-R ::= word ^"::=" Class+/gt
- | word ^"!::=" Class+/gt
-
-ec ::= [~\]\\\-\~] | escaped
-
-Class ::= Rewrite +/ bar => "alternatives"
-
-Rewrite ::= Rewritex
- | Rewritex ^"&" E+
- | Rewritex ^"&~" E+
-
-Rewritex ::= E+ => "rewrite"
- | E+ ^"=>" word
- | E+ ^"=>" quoted
- | E+ "=>" "()" => "wrap"
-
-range ::= ec => "range0" | ec ^"-" ec => "range0"
-gt !::= ">"
-bar !::= "|"
-E ::= word => "nonTerminalY"
- | [(][)] => "epsilon"
- | ^"{" Class+/gt "}"
- | "[" [\~]? range* "]" => "range"
- | E ^"*/" E
- | E ^"+/" E
- | E ^"?"
- | E ^"~/~"
-
- | E ^"-" E
-
- | ^"!" E
- | "^" quoted => "care"
- | ^"`" E
- | E ^"#"
- | quoted => "literal"
+s ::= ws grammar ws => "gram"
+ws !::= w**
+grammar ::= r +/ ws => "grammar"
+
+r ::= word ^"::=" alternatives /ws
+ | word ^"!::=" alternatives /ws
+
+alternatives ::= (conjuncts +/ (ws "|" ws)) +/ (ws ">" ws)
+
+conjuncts ::= sequence
+ | sequence ^"&" e*/ws /ws
+ | sequence ^"&~" e*/ws /ws