If $\bar{p}, \bar{q}, \bar{r}$ are three mutually perpendicular vectors of equal magnitude and if a vector $\bar{x}$ satisfies the equation $\bar{p} \times((\bar{x}-\bar{q}) \times \bar{p})+\bar{q} \times((\bar{x}-\bar{r}) \times \bar{q})+\bar{r} \times((\bar{x}-\bar{p}) \times \bar{r})=\bar{o}$ then $\bar{x}$ is