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)
10 sequence ::= e */ (w**)
11 > e */ (w**) ws ^"/" e
13 ss ::= es => "seq" | es ^"/" e /ws
16 | rewrite ^"&" e*/ws /ws
17 | rewrite ^"&~" e*/ws /ws
19 rewrite ::= sequence /ws => "rewrite"
20 | sequence ^"=>" (word|quoted) /ws
25 range ::= ec => "range"
28 e ::= word => "nonTerminal"
30 | ^"{" alternatives "}" /ws
36 | (e ws ^"**" > e ws ^"*")
38 | (e ws ^"++" > e ws ^"+")
45 > ^"(" alternatives ")" /ws
53 quoted ::= "\"" (([~\"\\] | escaped)+) "\""
55 escaped ::= "\\n" => "\n"