in parse table
parseTable :: NonTerminal -> Maybe Token -> [Symbol NonTerminal Token]
parseTable E    _                   = [SymNont E1, SymNont E']
pars
parseTable :: NonTerminal -> Maybe Token -> [Symbol NonTerminal Token]
parseTable E    _                   = [SymNont E1, SymNont E']
parseTable E    _                   = [SymNont E1, SymNont E']