Grammar re;
Lexer
a = 'a' 'b'?;
la = Longest(a);
sa = Shortest(a);
sla = Shortest(la);
dummy = 'X' (a|la|sa|sla);
blank = #10 | #13 | #32;
Parser
Ignored blank;
p = t+;
t = dummy |
a | la; //alt1 a | sa; //alt2 a | sla; //alt3 la | sa; //alt4 la | sla;