In various cases we required to specify the abstract syntax in the form of various sequence of symbols enclosed in the parentheses. And for the conversion of the prefix list to the abstract syntax, we are basically writting different parsers based on our needs. Solution In various cases we required to specify the abstract syntax in the form of various sequence of symbols enclosed in the parentheses. And for the conversion of the prefix list to the abstract syntax, we are basically writting different parsers based on our needs..