Prove, starting from the definition of convergence in probability : (a) $o_{p}(1)+o_{p}(1)=o_{p}(1)$ (b) $o_{p}(1) o_{p} (1)=0_{p} (1)$ (c) $g\left(\mu+o_{p} (1) ight)=g(\mu)+o_{p}(1), g(\cdot) $ is continuous at $\mu$. SP.JG. 006