{Topological,Differentiable,PseudoRiemannianSubmanifold}._repr_: Prin…

…t subsets as subsets

src/sage/manifolds/differentiable/differentiable_submanifold.py

@@ -208,6 +208,8 @@ def _repr_(self):
              3-dimensional differentiable manifold M
 
         """
+        if self is not self._manifold:
+            return "Open subset {} of the {}".format(self._name, self._manifold)
         if self._ambient is None:
             return super(DifferentiableManifold, self).__repr__()
         if self._embedded:

src/sage/manifolds/differentiable/pseudo_riemannian_submanifold.py

@@ -382,6 +382,8 @@ def _repr_(self):
              3-dimensional Lorentzian manifold M
 
         """
+        if self is not self._manifold:
+            return "Open subset {} of the {}".format(self._name, self._manifold)
         if self._ambient is None:
             return super(PseudoRiemannianManifold, self).__repr__()
         if self._embedded:

src/sage/manifolds/topological_submanifold.py

@@ -246,6 +246,8 @@ def _repr_(self):
              3-dimensional topological manifold M
 
         """
+        if self is not self._manifold:
+            return "Open subset {} of the {}".format(self._name, self._manifold)
         if self._ambient is self:
             return super(TopologicalManifold, self).__repr__()
         if self._embedded: