- self.assertEqual(self.expr.subs([(self.x, self.y), (self.y, self.x)]), 3 - self.x)
- self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
- self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}), 3 - self.z)
+ self.assertEqual(self.expr.subs([(self.x, self.y), (self.y, self.x)]),
+ -2*self.x + self.y + 3)
+ self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}),
+ 3 - self.z)
+ self.assertEqual(self.expr.subs({self.x: self.z, self.y: self.z}),
+ 3 - self.z)