diff --git a/TP03/tree/Makefile b/TP03/tree/Makefile
new file mode 100644
index 0000000..a4f1d15
--- /dev/null
+++ b/TP03/tree/Makefile
@@ -0,0 +1,24 @@
+PACKAGE = Tree
+MAINFILE = tree
+
+ifndef ANTLR4
+abort:
+	$(error variable ANTLR4 is not set)
+endif
+
+all: $(PACKAGE).g4
+	$(ANTLR4) $^ -Dlanguage=Python3 -visitor
+
+run: $(MAINFILE).py
+	python3 $^
+
+ex: $(MAINFILE).py
+	python3 $^ < true_example
+	python3 $^ < false_example
+
+test: all
+	python3 ./test_arith_visitor.py
+
+clean:
+	find . \( -iname "~" -or -iname "*.cache*" -or -iname "*.diff" -or -iname "log.txt" -or -iname "*.pyc" -or -iname "*.tokens" -or -iname "*.interp" \) -exec rm -rf '{}' \;
+	rm -rf $(PACKAGE)*.py
diff --git a/TP03/tree/MyTreeVisitor.py b/TP03/tree/MyTreeVisitor.py
new file mode 100644
index 0000000..2e379a0
--- /dev/null
+++ b/TP03/tree/MyTreeVisitor.py
@@ -0,0 +1,19 @@
+from TreeParser import TreeParser
+from TreeVisitor import TreeVisitor
+
+class MyTreeVisitor(TreeVisitor):
+    def visitTop(self, ctx:TreeParser.TopContext):
+        return self.visit(ctx.int_tree())
+
+    def visitLeaf(self, ctx:TreeParser.LeafContext):
+        return True
+
+    def visitNode(self, ctx:TreeParser.NodeContext):
+        return (
+            len(ctx.int_tree()) == 2
+            and all([self.visit(it) for it in ctx.int_tree()])
+        )
+
+
+del TreeVisitor
+del TreeParser
diff --git a/TP03/tree/false_example b/TP03/tree/false_example
new file mode 100644
index 0000000..7d5ad3f
--- /dev/null
+++ b/TP03/tree/false_example
@@ -0,0 +1 @@
+(42 12 1515 17)
diff --git a/TP03/tree/tree.py b/TP03/tree/tree.py
new file mode 100644
index 0000000..f76fce5
--- /dev/null
+++ b/TP03/tree/tree.py
@@ -0,0 +1,26 @@
+from TreeLexer import TreeLexer
+from TreeParser import TreeParser
+# from TreeVisitor import TreeVisitor
+from MyTreeVisitor import MyTreeVisitor
+
+from antlr4 import InputStream, CommonTokenStream
+import sys
+
+# example of use of visitors to parse arithmetic expressions.
+# stops when the first SyntaxError is launched.
+
+
+def main():
+    lexer = TreeLexer(InputStream(sys.stdin.read()))
+    stream = CommonTokenStream(lexer)
+    parser = TreeParser(stream)
+    tree = parser.int_tree_top()
+    visitor = MyTreeVisitor()
+    is_binary_tree: bool = visitor.visit(tree)
+    print("Is it a binary tree ? " + str(is_binary_tree))
+
+
+if __name__ == '__main__':
+    main()
+
+
diff --git a/TP03/tree/true_example b/TP03/tree/true_example
new file mode 100644
index 0000000..a5d8857
--- /dev/null
+++ b/TP03/tree/true_example
@@ -0,0 +1 @@
+(12 (13 (14 15 15) 16) (17 18 (19 20 1)))