Grammar re;
Lexer
a = 'a';
b = 'a' 'b' 'a' 'c'; //alt1 //alt2
//alt1 b = 'a' 'b' 'a'* 'c';
//alt2 b = 'a'* 'b' 'a' 'c';
blank = #10 | #13 | #32;
Parser
Ignored blank;
t = a | b;