2. A token of a programming language is a meaningful symbol of the language. Tokens include numeric literals, string literals, names, operators (like + or %), separators (like semicolons), grouping indicators (like parentheses and brackets), and reserved words, like if, while, end, and so forth. The set of tokens of a programming language are usually a regular language. Consequently tokens are often described by regular expressions. Also, the portion of a language translator that reads programs as a stream of characters and converts this stream into a stream of tokens is based on a finite automaton. The part of a program that does this job is called a lexical analyzer or tokenizer. In a little while you will have a programming assignment in which you are asked to implement a desk calculator. You will need to write a tokenizer for the desk calculator language that simulates a DFA to recognize tokens. The desk calculator is very simple: it can evaluate simple postfix expressions and print the result, or assign values to variables that can be used in later expressions. The tokens of this language are defined as follows (using Unix regular expression notation and variables as abbreviations for longer regular expressions). digit [0-9] letter = [a-zA-Z] variable -letter (letter + digit)* number- digit digit* | digit digit* \, digit" EOL IIn token variable | number | 1/IEOL Make a DFA to recognize this language. The alphabet is the ASClI character set