Grammar y;

Lexer

a = 'a' Any;
b = 'b' (Any - 'b');
c = 'c' (#0..'c');
d = 'd' (Any-(#0..'c'));
e = 'e' 'e'...;

blank = #10 | #13 | #32;
Parser
Ignored blank;

p = t+;
t = a | b | c | d | e;