# sympy__sympy-20590
# Loki Mode Multi-Agent Patch
# Attempts: 1

--- a/sympy/printing/defaults.py
+++ b/sympy/printing/defaults.py
@@ -3,6 +3,8 @@ from .pretty import pprint
 
 class DefaultPrinting:
     """
     The default implementation of printing for SymPy classes.
     """
+    __slots__ = ()
+
     def __str__(self):
         return sstr(self, order=None)