diff --git a/lexer.py b/lexer.py
index 52abb85..c695abe 100644
--- a/lexer.py
+++ b/lexer.py
@@ -26,28 +26,53 @@ reserved = {
     'Goto': 'GOTO',
 }
 
-literals = '+-*/%(){}[]=,'
 # List of token names
 tokens = [
+    'PLUS',
+    'MINUS',
+    'TIMES',
+    'DIVIDE',
+    'MODULO',
+    'LPAREN',
+    'RPAREN',
+    'LCURBRA',
+    'RCURBRA',
+    'LSQRBRA',
+    'RSQRBRA',
+    'ASSIGN',
+    'COMMA',
     'STRING',
     'NUMBER',
     'ISEQUAL',
     'PLUSASSIGN',
     'MINUSASSIGN',
     'TIMESASSIGN',
-    'DIVASSIGN',
-    'MODASSIGN',
+    'DIVIDEASSIGN',
+    'MODULOASSIGN',
     'NEWLINE',
     'ID',
 ] + list(reserved.values())
 
 # common regex
+t_PLUS = r'\+'
+t_MINUS = r'\-'
+t_TIMES = r'\*'
+t_DIVIDE = r'\/'
+t_MODULO = r'\%'
+t_LPAREN = r'\('
+t_RPAREN = r'\)'
+t_LCURBRA = r'\{'
+t_RCURBRA = r'\}'
+t_LSQRBRA = r'\['
+t_RSQRBRA = r'\]'
+t_ASSIGN = r'\='
+t_COMMA = r'\,'
 t_ISEQUAL     = r'=='
 t_PLUSASSIGN  = r'\+='
 t_MINUSASSIGN = r'\-='
 t_TIMESASSIGN = r'\*='
-t_DIVASSIGN   = r'/='
-t_MODASSIGN   = r'\%='
+t_DIVIDEASSIGN   = r'/='
+t_MODULOASSIGN   = r'\%='
 # Comments
 t_ignore_COMMENT = r'//.*'