2. Research to write down the rule of a variable identifier in the following programming languages and write down the regular grammar for that rule. For example, as elaborated in the class, the rule of a variable identifier in C is "start either by or any alphabetic character, and then follow either by_, any alphabetic character, or number", and its regular grammar is: [_a-zA-2] [a-zA-ZO-9]* a. JavaScript i. (5 points) Rule: Solution: ii. (5 points) Regu grammar: Solution: b. PHP (5 points) Rule: i. Solution: (5 points) Regular grammar: i. Solution: C. Scheme i. (5 points) Rule: Solution: (5 points) Regular grammar: ii. Solution: d. GoLang i. (5 points) Rule: Solution: (5 points) Regular grammar: ii. Solution