THE CHALLENGE Consider the following grammar: + | ::= * I ()| sid> sid> ::= albl... Iz 1. State in your own words what kinds of sentences (strings) these productions describe. (5 points) 2. Give 3 examples of valid strings, and 3 examples of invalid strings, according to the grammar. (5 points) 3. Write a lexical analyzer (scanner) program for this BNF. (20 points) This scanner should prompt the user to input a string, then output a list of tokens and lexemes , one per line, from the input string according to the above grammar. If something is wrong in the input stream it should output an error message of some kind and abandon the scan. HINT: This grammar has a special property: every lexeme consists of exactly one character! Therefore this scanner will be much simpler than the one shown in 4.2 of your textbook. You may want to refer to that example, or your Week 4 recognizer solution, for ideas about how to implement this scanner. THE EVIDENCE For #1 and #2, you must submit a WORD document into which you have typed your answers. You can answer both questions in the same file! For #3 (program), you must submit: code - file save, or copy/paste into Notepad from your IDE or editor. I must be able to open or copy/paste the code from your submission to "desk-check" and run it myself. Runs of your program showing it correctly handled TWO test cases you developed in #2. One of the test cases should be an example of a valid string; the other test case should be an invalid string. Do file saves from your IDE or OS of choice; screen shots also are acceptable