Hi all
Can anyone please explain why this is a CFG? Here the set of non-terminals = {S} and set of pre-terminals is also = {S} (as in lexical rule, S -> a, 'S' appears on L.H.S.). However, shouldn't the set of preterminals (or PoS tags) be a "proper subset" of non-terminals by definition? In this case they are equal.
Thank you for your time and consideration
Regards
Abhilaksh