2. [10 marks] Give a context-free grammar that generates the language of properly nested parentheses and braces. Le, for each open open parenthese/brace there is a closing one, and a closing brace/parenthese cannot occur until all open braces/parentheses within are closed. le., ? = {"(',')','(',99 and words such as ((){}) and ( () ()){()} are in the language, but words such as f),)(, and O are not