def fdiff(self, argindex=1):
        z = self.args[0]
        return (elliptic_e(z) - (1 - z)*elliptic_k(z))/(2*z*(z - 1))
dataset/ETHPy150Open sympy/sympy/sympy/functions/special/elliptic_integrals.py/elliptic_k.fdiff/swapped operands of `-`