1 s ::= ws grammar ws => "gram"
3 grammar ::= r +/ ws => "grammar"
4 r ::= word ^"::=" alternatives /ws
5 | word ^"!::=" alternatives /ws
7 alternatives ::= equiAlt +/ (ws ">" ws)
8 equiAlt ::= conjuncts +/ (ws "|" ws)
14 ss ::= es => "seq" | es ^"/" e /ws
17 | rewrite ^"&" e*/ws /ws
18 | rewrite ^"&~" e*/ws /ws
20 rewrite ::= sequence /ws => "rewrite"
21 | sequence ^"=>" word /ws
22 | sequence ^"=>" quoted /ws
27 range ::= ec => "range"
30 e ::= word => "nonTerminal"
32 | ^"{" alternatives "}" /ws
38 | (e ws ^"**" > e ws ^"*")
40 | (e ws ^"++" > e ws ^"+")
47 > ^"(" alternatives ")" /ws
55 quoted ::= "\"" (([~\"\\] | escaped)+) "\""
57 escaped ::= "\\n" => "\n"