#define ALPHA_OFFSET 5
#define TOK_LEN 3
#define INVALID_ARG "invalid"
#define DIFF_ARG "diff"
#include <string.h>
#include <stdio.h>
#include "lex.yy.c"

extern int line_number, column_number;
extern char *yytext;

int main(int argc, char *argv[]);
char *is_tok(int argc, char *argv[]);
#define ALPHA_OFFSET 5