def __neg__(self):
        x, y, z = self._v
        return self.from_floats(-x, -y, -z)
expression : NOT expression
dataset/ETHPy150Open PythonProgramming/Beginning-Game-Development-with-Python-and-Pygame/Chapter 10/gameobjects/vector3.py/Vector3.__neg__--crossover with--dataset/ETHPy150Open armon/pypred/pypred/parser.py/p_expression_not