Given This Code of a Lexical Analyzer in Python:

import ply.lex as lex

t_ID=r'[a-zA-Z0-9]'

t_NUM=r'[0-9]'

t_LPAREN = r'\('

t_RPAREN= r'\)'

t_LBRACE=r'{'

t_RBRACE=r'}'

t_NE=r'!='

t_EQ=r'=='

t_ARROW=r'=>'

t_LE=r'

t_GE=r'>='

t_BECOMES=r'='

t_LT=r'

t_GT=r'>'

t_PLUS=r'\+'

t_MINUS=r'-'

t_STAR=r'\*'

t_SLASH=r'/'

t_PCT=r'%'

t_COMMA=r','

t_SEMI=r';'

t_COLON=r':'

t_ignore = ' \t'

keywords = {

'def':'DEF',

'var':'VAR',

'Int':'INT',

'if':'IF',

'else':'ELSE',

}

tokens = ["ID", "DEF", "VAR", "INT", "IF", "ELSE", "NUM", "LPAREN",

"RPAREN", "LBRACE", "RBRACE", "BECOMES", "EQ", "NE", "LT", "GT",

"LE", "GE", "PLUS", "MINUS", "STAR", "SLASH", "PCT", "COMMA", "SEMI", "COLON", "ARROW"]

def t_DEF(t):

r'[a-zA-Z_][a-zA-Z_0-9]*'

t.type = keywords.get(t.value, 'DEF')

return t

def t_VAR(t):

r'[a-zA-Z][a-zA-Z_0-9]*'

t.type = keywords.get(t.value, 'VAR')

return t

def t_INT(t):

r'[a-zA-Z][a-zA-Z_0-9]*'

t.type = keywords.get(t.value, 'INT')

return t

def t_IF(t):

r'[a-zA-Z][a-zA-Z_0-9]*'

t.type = keywords.get(t.value, 'IF')

return t

def t_ELSE(t):

r'[a-zA-Z][a-zA-Z_0-9]*'

t.type = keywords.get(t.value, 'ELSE')

return t

t_ignore_COMMENT = r'\#.'

def t_newline(t):

r' +'

t.lexer.lineno += len(t.value)

def t_error(t):

print("Illegal character '%s'" % t.value[0])

t.lexer.skip(1)

lexer = lex.lex()

file = open("test_file.txt", 'r')

for line in file:

lexer.input(line)

while True:

tok = lexer.token()

if not tok:

break

print(tok)

file.close()

Add the parsing code using PLY to recognize the following grammar rules: