diff --git a/TP02/ariteval/Arit.g4 b/TP02/ariteval/Arit.g4
index 53e1d98..775eb97 100644
--- a/TP02/ariteval/Arit.g4
+++ b/TP02/ariteval/Arit.g4
@@ -13,9 +13,35 @@ class UnknownIdentifier(Exception):
 class DivByZero(Exception):
     pass
 
+def checkID(s):
+  if s not in idTab:
+    raise UnknownIdentifier(s)
+
+def getID(s):
+  try:
+    return idTab[s]
+  except IndexError:
+    raise UnknownIdentifier(s)
+
 }
 
-prog: ID {print("prog = "+str($ID.text));} ;
+prog: e0=expr EOF {print($e0.text, "=>", $e0.val)};
+
+expr returns [int val]:
+  | e=expr '+' t=term {$val = $e.val + $t.val}
+  | t=term {$val = $t.val}
+  ;
+
+term returns [int val]:
+  | t=term '*' f=fxpr {$val = $t.val * $f.val}
+  | f=fxpr {$val = $f.val}
+  ;
+
+fxpr returns [int val]:
+  | ID {$val = getID($ID.text)}
+  | INT {$val = int($INT.text)}
+  | '(' e=expr ')' {$val = $e.val}
+  ;
 
 
 COMMENT
diff --git a/TP02/demo_files/ex1/Example1.g4 b/TP02/demo_files/ex1/Example1.g4
index 0f526a4..05a6dd5 100644
--- a/TP02/demo_files/ex1/Example1.g4
+++ b/TP02/demo_files/ex1/Example1.g4
@@ -4,6 +4,8 @@ lexer grammar Example1;
 
 OP : '+'| '*' | '-' | '/' ;
 DIGIT : [0-9] ;
+LPAR : '(' ;
+RPAR : ')' ;
 LETTER : [A-Za-z] ;
 ID : LETTER (LETTER | DIGIT)* ;             // match idents
 WS : [ \t\r\n]+ -> skip ; // skip spaces, tabs, newlines
diff --git a/TP02/python/typecheck.py b/TP02/python/typecheck.py
index 58f8288..2761421 100644
--- a/TP02/python/typecheck.py
+++ b/TP02/python/typecheck.py
@@ -2,7 +2,7 @@
 # name: type
 int_variable: int
 float_variable: float
-int_variable = 4.2  # Static typing error, but no runtime error
+int_variable = 4  # Static typing error, but no runtime error
 float_variable = 42.0  # OK
 float_variable = int_variable  # OK
 
@@ -12,5 +12,4 @@ def int_to_string(i: int) -> str:
     return str(i)
 
 
-print(int_to_string('Hello'))  # Static typing error, but no runtime error
-print(int_to_string(42) / 5)  # Both static and runtime error
+print(int_to_string(42))  # Both static and runtime error