amend

tensordict/base.py

@@ -7179,7 +7179,7 @@ def sub(self, other: TensorDictBase | float, alpha: float | None = None):
         if alpha is not None:
             vals = torch._foreach_sub(val, other_val, alpha=alpha)
         else:
-            vals = torch._foreach_sub(vals, other_val)
+            vals = torch._foreach_sub(val, other_val)
         items = dict(zip(keys, vals))
         return self._fast_apply(
             lambda name, val: items.get(name, val),

test/test_tensordict.py

@@ -2437,6 +2437,25 @@ def dummy_td_1(self):
     def dummy_td_2(self):
         return self.dummy_td_0.apply(lambda x: x + 2)
 
+    def test_ordering(self):
+
+        x0 = TensorDict(
+            {
+                "y": torch.zeros(3),
+                "x": torch.ones(3)
+            }
+        )
+
+        x1 = TensorDict(
+            {
+                "x": torch.ones(3),
+                "y": torch.zeros(3)
+            }
+        )
+        assert ((x0+x1)["x"] == 2).all()
+        assert ((x0*x1)["x"] == 1).all()
+        assert ((x0-x1)["x"] == 0).all()
+
     @pytest.mark.parametrize("locked", [True, False])
     def test_add(self, locked):
         td = self.dummy_td_0