def is_qualified_relation_frame(self, x):
    """Test if x is a CVT-node-like frame with a main object."""
    if not self.is_nested_frame(x):
      return False
    if isinstance(x['is'], (sling.Frame, numbers.Number)):
      return True
    return False
Test if x is a CVT-node-like frame with a main object.
language/templama/sling2facts.py